WO2022261294A1

WO2022261294A1 - Bow and stern thrusters for watercraft

Info

Publication number: WO2022261294A1
Application number: PCT/US2022/032795
Authority: WO
Inventors: Michael Railey
Original assignee: Seajet Propulsion, Inc.
Priority date: 2021-06-10
Filing date: 2022-06-09
Publication date: 2022-12-15

Abstract

A watercraft is described herein. The watercraft comprises a body including an outer surface having at least one recess extending generally inward. The watercraft also comprises a cassette disposed at least partially within the at least one recess, the cassette housing a drive system including at least one electric motor and at least one impeller coupled to the at least one electric motor. The cassette further comprising a surface having a water intake and a water exhaust port, and wherein the cassette is disposed within the at least one recess such that the base surface of the cassette substantially matches the adjacent outer surface of the body around the recess to form a smooth body outer surface having water intake and exhaust ports therein.

Description

BOW AND STERN THRUSTERS FOR WATERCRAFT PRIORITY APPLICATION [0001] This application claims priority to U.S. Provisional Patent Application No. 63/209,103, filed June 10, 2021, which is incorporated herein by reference in its entirety and for all purposes. BACKGROUND Field [0002] This application is related to propulsion systems for watercraft. In particular, this application is related to propulsion systems, such as thrusters, that can be positioned on the bow and/or stern of a watercraft for enhanced maneuverability. Description [0003] Watercraft, such as boats, can include various systems for propulsion and steering. Typically, watercraft include a main drive located at or near the stern and oriented to provide thrust in forward and backward directions. The main drive can be used with a rudder, also typically located at or near the stern, to provide maneuverability. SUMMARY [0004] Watercraft, such as boats, can be configured to include thrusters positioned on or near the bow or stern thereof to provide improved maneuverability, especially during docking or other low speed maneuvers. In some embodiments, the thrusters can be configured as removable cassettes that can be removably installed into corresponding recesses formed into the hull of a watercraft. The removable cassettes can include, for example, a water intake and a water exhaust. The removable cassettes can be configured to draw water in in through the water intake and to accelerate that water out through the water exhaust (for example, as a jet of water) in order to provide a propulsive force. In some embodiments, the removable cassettes can include a motor that is configured to drive an impeller that is positioned in a fluid path between the water intake and the water exhaust. In some embodiments, the cassettes need not be removable and can instead be permanently integrated into the hull of a watercraft. with different orientations to provide different thrust directions. For example, cassettes can be positioned on or near the bow and/or stern of the watercraft and oriented to provide lateral propulsion that may facilitate steering and/or low speed maneuverability to provide enhanced control and maneuverability during docking. In some instances, the cassettes can be positioned on the watercraft in a manner that provides thrust in forward and/or backward directions, and thus can be used as (or to supplement) the main drive of the watercraft. [0006] For example, in some embodiments, a watercraft can include a hull configured to float in water and at least one recess formed on the hull and extending generally inward. The watercraft can also include at least one cassette disposed at least partially within the at least one recess, the cassette housing a drive system including at least one electric motor and at least one impeller coupled to the at least one electric motor, the cassette further comprising a water intake port and a water exhaust port, wherein the at least one cassette is disposed within the at least one recess such that the base surface of the cassette substantially matches an adjacent outer surface of the hull around the recess to form a smooth body outer surface having water intake and exhaust ports therein. [0007] In some embodiments, the at least one recess comprises a first recess positioned on a port side of the hull proximal to a bow of the hull and a second recess positioned on a starboard side of the hull proximal to the bow of the hull, and the at least one cassette comprises a first cassette disposed within the first recess and a second cassette disposed within the second recess. In some embodiments, the first cassette is configured to generate a propulsive force that moves the bow of the watercraft in a starboard direction, and the second cassette is configured to generate a propulsive force that moves the bow of the watercraft in a port direction. In some embodiments, each of the first and second recess are generally oriented in a horizontal position. In some embodiments, each of the first and second recess are generally oriented in a vertical position. [0008] In some embodiments, the at least one recess comprises a first recess positioned on a port side of the hull proximal to a stern of the hull and a second recess positioned on a starboard side of the hull proximal to the stern of the hull, and the at least one cassette comprises a first cassette disposed within the first recess and a second cassette generate a propulsive force that moves the stern of the watercraft in a starboard direction, and the second cassette is configured to generate a propulsive force that moves the stern of the watercraft in a port direction. In some embodiments, each of the first and second recess are generally oriented in a horizontal position. In some embodiments, each of the first and second recess are generally oriented in a vertical position. [0009] In some embodiments, the at least one recess comprises a first recess positioned on an underside side of the hull proximal to a stern of the hull and a second recess positioned on an underside side of the hull proximal to the stern of the hull, and the at least one cassette comprises a first cassette disposed within the first recess and a second cassette disposed within the second recess. [0010] In some embodiments, the cassette comprises at least one motor controller. In some embodiments, the at least one motor controller is coupled to a power source. [0011] In some embodiments, the watercraft further comprises an insert disposed in the at least one recess. In some embodiments, the insert comprises a protrusion and wherein at least a portion of the cassette comprises an indentation. In some embodiments, at least a portion of the protrusion is at least partially received within the indentation. In some embodiments, the cassette is removably coupled to the insert. [0012] For purposes of this summary, certain aspects, advantages, and novel features are described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize the disclosures herein may be embodied or carried out in a manner that achieves one or more advantages taught herein without necessarily achieving other advantages as may be taught or suggested herein. [0013] All of the embodiments described herein are intended to be within the scope of the present disclosure. These and other embodiments will be readily apparent to those skilled in the art from the following detailed description, having reference to the attached figures. The invention is not intended to be limited to any particular disclosed embodiment or embodiments. [0014] These and other features, aspects, and advantages of the bow and stern thruster devices, systems, methods, and related watercraft will be described below with reference to drawings of certain embodiments, which are intended to illustrate, but not to limit, the present disclosure. It is to be understood that the accompanying drawings, which are incorporated in and constitute a part of this specification, are for the purpose of illustrating concepts disclosed and may not be to scale. [0015] FIG. 1 is a perspective view of an embodiment of a removable motorized cassette that can be used, for example, as a bow or stern thruster on a watercraft. [0016] FIG.2 is a perspective view of the removable motorized cassette of FIG. 1 as well as a corresponding recess that can be formed into the hull of a watercraft and configured to receive the cassette. [0017] FIG. 3 illustrates the removable motorized cassette of FIG. 1 installed into the corresponding recess formed into the hull of the watercraft. [0018] FIG. 4 is a side view of an embodiment of a watercraft including a removable motorized cassette, such as the cassette of FIG. 1, installed in a generally vertical orientation at the bow of the watercraft. [0019] FIG. 5 is a side view of an embodiment of a watercraft including a removable motorized cassette, such as the cassette of FIG.1, installed in a generally horizontal orientation at the bow of the watercraft. [0020] FIG. 6 is a back view of an embodiment of a watercraft including two removable motorized cassettes, which each may be configured as the cassette of FIG. 1, installed in a generally horizontal orientation at the stern of the watercraft. [0021] FIG. 7 is a bottom view of an embodiment of a watercraft including two removable motorized cassettes, which each may be configured as the cassette of FIG. 1, installed in a generally horizontal orientation on the underside of the watercraft. [0022] FIG. 8 is a cutaway view of the removable motorized cassette of FIG. 1, illustrating a portion of the interior thereof. [0023] FIG. 9 is a side exploded view of some components of the removable motorized cassette of FIG. 1. embodiment of a removable motorized cassette that includes a directional exhaust attachment. [0025] FIG.11 is a perspective view of an embodiment of a dual pump motorized cassette. [0026] FIG. 12 is a perspective view of the dual pump motorized cassette of FIG. 11. [0027] FIG. 13 is an exploded view of an embodiment of a dual pump motorized cassette. [0028] FIG.14 is a perspective cutaway view of the dual pump motorized cassette of FIG.13. DETAILED DESCRIPTION [0029] This application relates to motorized cassettes which can be used as, for example, bow or stern thrusters for watercraft, such as boats. In some embodiments, the motorized cassettes are configured to be removably installed on or near the bow or stern thereof to provide improved maneuverability, especially during docking or other low speed maneuvers. For example, the hull of a watercraft can be configured with recesses that are configured to receive the motorized cassettes. In some embodiments, the motorized cassettes need not be removable and can instead be permanently integrated into the hull of a watercraft. [0030] In some embodiments, the motorized cassettes can include a water intake and a water exhaust. The motorized cassettes can be configured to draw water in in through the water intake and to accelerate that water out through the water exhaust (for example, as a jet of water) in order to provide a propulsive force. In some embodiments, the motorized cassettes can include a motor that is configured to drive an impeller that is positioned in a fluid path between the water intake and the water exhaust. [0031] The motorized cassettes can be oriented on the watercraft at different positions and with different orientations to provide different thrust directions. For example, cassettes can be positioned on or near the bow and/or stern of the watercraft and oriented to provide lateral propulsion that may facilitate steering and/or low speed maneuverability to provide enhanced control and maneuverability during docking. In some instances, the forward and/or backward directions, and thus can be used as (or to supplement) the main drive of the watercraft. [0032] Small boats are usually maneuvered by a propulsion system located in the rear of the boat. Generally a steerable outboard engine or rudder are pivoted to one direction or the other to maneuver the boat. Because the thrust and steering are provided at the rear of the boat, the motion causes a consequent movement of the bow to the opposite side. In small, cramped spaces (e.g., at a dock or marina), maneuvering the boat is difficult at best, even for many skilled operators, and many accidents such as ramming another watercraft or the dock occur. The problem of maneuverability exists because the bow of the boat responds only to the engine and rudder in the rear. [0033] Conventional auxiliary maneuvering systems that enable the operator to steer the bow of the boat as well as the stern, making the boat more maneuverable, have had many limitations. Some auxiliary steering mechanisms include externally mounted bow and stern thrusters that have one or more propellers driven by a reversible electric motor that provides thrust in either direction. However, since these externally mounted systems include an unprotected unit protruding from the bow, they may catch and snag lines or other debris in the water, and the motor will be submerged constantly. Additionally, externally mounted bow and stern thrusters are simply bolted on to the bow or stern and may cause drag while traveling. [0034] Another auxiliary maneuvering system requires the cutting of large holes through the bow of the boat to install a propeller in a tube that extends transverse to the bow of the watercraft. These systems can be disadvantageous in that the large transverse tunnel with the propeller enclosed therein can create a water trap, which in turn increases the drag on the boat’s hull, making the watercraft more difficult to propel through the water. The speed of the boat, therefore, is lowered and fuel consumption increased. [0035] These and other such problems are reduced with a motorized cassette placed in a recess of the hull such that the surface of the cassette is smooth and flush with the surface of the hull as described herein. [0036] The general purpose of many embodiments described herein is to provide a bow or stern thruster which can be affixed to a recess in the hull of a boat or other watercraft system is provided as a separately housed cassette. These embodiment may allow the cassette to be retrofitted to existing watercrafts or may be compatible with new watercrafts with recesses in the hull. In some embodiments, the cassettes may be well suited for watercrafts between 20 and 50 feet, as many watercraft over 50 feet may come equipped with bow and stern thrusters (external or tunnel) and many watercraft under 20 feet may not require such increased maneuverability. The cassettes can, however, be used with larger or smaller watercrafts. [0037] The cassettes may house motors, control electronics, impellers, and associated drive hardware. They may connect to the watercraft battery or other power source so that there are no battery limitations. It may be made removable and/or exchangeable. The cassette can be made to fit flush with the hull of the boat so that there are no protruding parts or tunnels which may create drag and reduced speeds. Such designs may have hydrodynamic benefits as well as aesthetic benefits. Such cassettes can improve safety over mechanisms that use blade propellers. The cassettes may employ waterjet technology that offers decreased sound over tunnel or externally mounted bow thrusters. Waterjet suction may provide increased stabilization in rough water conditions. Such a cassette may also be used in a variety of watercraft, not just in boats. [0038] These and other features of the bow and stern thruster devices, systems, methods, and related watercraft described herein will become more fully apparent from the following description of specific embodiments illustrated in the figures. These embodiments are intended to illustrate the principles of this disclosure, and this disclosure should not be limited to merely the illustrated examples. The features of illustrated embodiments can be modified, combined, removed, and/or substituted as will be apparent to those of ordinary skill in the art upon consideration of the principles of this disclosure. [0039] FIG. 1 is a perspective view of an embodiment of a removable motorized cassette 100. The cassette 100 can be used, for example, as a bow or stern thruster on a watercraft. In some embodiments, the cassette 100 is configured to provide steering forcing for assisting in maneuvering the water craft. In some embodiments, the cassette 100 is configured to be used as or to supplement the main drive of the watercraft by, for example, embodiment, the cassette 100 is illustrated as a removable module that can be selectively installed into a recess formed into the hull of a watercraft, for example, as will be described in FIGs. 2 and 3 below. In other embodiments, the cassette 100 can comprise a module, device, unit, or system that is permanently installed in the hull of a watercraft, and thus, not removable. [0040] As shown in FIG.1, the cassette 100 may comprise a housing 101. The housing 101 may be configured to enclose various internal components of the cassette 100, which will be described in more detail below. In some embodiments, the housing 101 comprises a watertight housing that is configured to protect at least some of the internal components from moisture, which can be especially important considering that, during use, the cassette 100 will generally be submerged in the water. [0041] In some embodiments, the housing 101 of the cassette 100 may comprise dimensions of approximately six inches wide, five inches deep, and thirty inches long. These dimensions are provided only by way of example, and the housing 101 of the cassette 100 can be configured with other dimensions as well. For example, in some embodiments, the cassette 100 comprises a width of about 3 inches, about 4 inches, about 5 inches, about 6 inches, about 6 inches, about 7 inches, about 8 inches, about 9 inches, about 10 inches, or longer. In some embodiments, the cassette 100 comprises a width of at most 3 inches, at most 4 inches, at most 5 inches, at most 6 inches, at most 6 inches, at most 7 inches, at most 8 inches, at most 9 inches, or at most 10 inches. In some embodiments, the cassette 100 comprises a depth of about 3 inches, about 4 inches, about 5 inches, about 6 inches, about 6 inches, about 7 inches, about 8 inches, about 9 inches, about 10 inches, or longer. In some embodiments, the cassette 100 comprises a depth of at most 3 inches, at most 4 inches, at most 5 inches, at most 6 inches, at most 6 inches, at most 7 inches, at most 8 inches, at most 9 inches, or at most 10 inches. In some embodiments, the cassette 100 comprises a length of about 10 inches, about 12.5 inches, about 15 inches, about 17.5 inches, about 20 inches, about 22.5 inches, about 25 inches, about 27.5 inches, about 30 inches, about 32.5 inches, about 35 inches, about 37.5 inches, about 40 inches, about 42.5 inches, about 45 inches, about 47.5 inches, about 50 inches or longer. In some embodiments, the cassette 100 comprises a length of at most 10 inches, at most 12.5 inches, at most 15 inches, at most 17.5 inches, at most 20 inches, at most 22.5 inches, at most most 37.5 inches, at most 40 inches, at most 42.5 inches, at most 45 inches, at most 47.5 inches, or at most 50 inches. Where the housing 101 of the cassette 100 is configured to be removably or permanently installed into a recess (see FIGs.2 and 3), the recess may have dimensions that correspond to those of the housing with small tolerances that allow the housing 101 to be inserted into the recess. [0042] In the illustrated embodiment, the housing 101 of the cassette 100 includes rounded corners. Rounded corners may provide more uniform strength than square or rectangular cassettes with sharp corners. Additionally, the rounded corners are more amenable to removable and/or exchangeable cassettes than sharp corners. In some embodiments, however, the housing 101 of the cassette 100 can be rectangular or square. [0043] With continued reference to FIG.1, the cassette 100 can include one or more intake ports 102 and one or more exhaust ports 104. In the illustrated embodiment, a single intake port 102 and a single exhaust port 104 are shown. The cassette 100 can be configured to draw in water through the intake port 102 and accelerate it out of the exhaust port 104, for example, as a jet of water. The jet of water can provide a propulsive force. Internal to the housing 101, the cassette 100 can include components configured to accelerate the water. For example, the cassette 100 can include one or more pump housings, one or more motor controllers, one or more motor shafts, one or more motors, one or more wires 106 to connect to a power supply, and/or one or more impellers. The orientation and design of these components may be configured as described below such that the cassette 100 may propel a watercraft relative to a body of water, for example, to aid in maneuvering a boat in a docking area. [0044] Examples of these internal components will be described in more detail below with respect to FIGs.8-14. Additional detail regarding the internal components that can be used with some embodiments of the cassette 100 are described in U.S. Pat. No.10,689,077, entitled “Water Pump for Watercraft,” which issued on June 23, 2020, from U.S. Application No.16/570,967, filed September 13, 2019. Both U.S. Pat. No.10,689,077 and U.S. Application No.16/570,967 are incorporated herein by reference in their entireties and for all purposes. one or more grates 103 disposed over the intake ports 102 of the housing 101. The grates 103 can limit access to the impeller and shaft to protect these components and/or prevent a user from inadvertently contacting these components during use. In some embodiments, the grate 103 can be coupled to one or more magnetic switches that can deactivate the motors when the pump housing and/or grate 103 are separated from the cassette base 101. Therefore, the one or more magnetic switches may prevent the cassette 100 from operating without the optional grate 103 in place. [0046] FIG. 2 is a perspective view of the 100 as well as a corresponding recess 204 that can be formed into the hull 200 of a watercraft and configured to receive the cassette 100. As shown, the recess 204 can be formed into the hull 200 with a shape that corresponds generally the shape of the housing 101 of the cassette 100. The recess 204 can be configured so as to be watertight, such that water does not leak into the hull 202 through the recess 204. In some embodiments, the recess 204 is formed into the hull 202 during the original manufacture of the hull 202. In other embodiments, the recess 204 may be formed into the hull 202 after manufacture, for example, as part of an aftermarket modification of the hull 202. FIG. 2 illustrates the recess 204 and the cassette 100 prior to installation of the cassette 100 into the recess 204. In some embodiments, to install the cassette 100, the cassette 100 is inserted into the recess 204. The cassette 100 and/or the recess 204 can be configured with mechanisms that secure the cassette 100 into the recess 204, such as latches. In some embodiments, installation of the cassette 100 into the recess 204 establishes electrical connections between the cassette 100 and an electrical system of the watercraft, thereby allowing power and communications signals to pass between the watercraft and the cassette 100. In some embodiments, the cassette 100 includes its own power source and a wireless communications circuit. In such embodiments, electrical connections between the cassette 100 and the watercraft are not needed. [0047] FIG. 3 illustrates the cassette 100 installed into the corresponding recess 204 formed into the hull 202 of the watercraft. As shown, in some embodiments, when the substantially flush with the surface of the hull 202. This configuration can maintain the hydrodynamic shape of the hull 202. In some embodiments, when installed, the upper surface of the housing 101 of the cassette 100 extends no more than 1/8 of an inch, 1/4 an inch, 3/8 an inch, 1/2 an inch, 5/8 an inch, 3/4 an inch, 7/8 an inch, or inch above the surface of the hull 202. [0048] FIG. 4 is a side view of an embodiment of a watercraft 200 including a removable motorized cassette, such as the cassette 100 of FIG. 1, installed in a generally vertical orientation at the bow of the watercraft 200. Although only one side of the watercraft 200 is shown, the motorized cassette 100 may be installed on both sides of the bow. As shown, the cassette 100 is vertically situated from a side view of the watercraft 200 on the right or starboard side of the hull 202 near the bow with the intake port 102 located above the exhaust port 104. The cassette 100 is also situated such that it is flush with the tapered surface of the hull near the bow. In such a configuration, a motor of the cassette 100 can drive an impeller to draw water through the intake port 102 and a pump housing and out the exhaust port 104 to propel the watercraft 200 to the left or port direction. Such a configuration may also stabilize the watercraft 200 in rough water conditions by propelling the bow of the watercraft 200 up or down. The same propulsion may also help the watercraft 200 hold a position in the water. Other orientations and configurations for the cassette 100 are possible to allow for turning or lateral movement of the watercraft 200 from the bow. [0049] FIG. 5 is a side view of an embodiment of a watercraft 200 including a removable motorized cassette, such as the cassette 100 of FIG. 1, installed in a generally horizontal orientation at the bow of the watercraft. In the illustrated configuration, the cassette 100 is situated horizontally, or substantially parallel with a water line, and in such a configuration, the cassette 100 will propel the watercraft 200 forward as well as to the left. In this horizontal configuration, the exhaust port 104 may be positioned so as to minimize potential forward propulsion. [0050] In some embodiments, multiple cassettes 100 may be located on either side of the hull near the bow to provide extra propulsion. As discussed above, the bow cassettes 100 may provide increased maneuverability in docking areas. removable motorized cassettes, which each may be configured as the cassette 100 of FIG. 1, installed in a generally horizontal orientation at the stern of the watercraft. In this example, two motorized cassettes 100 are received in respective recesses in the stem portion of a watercraft 200. As shown, the motorized cassette 100 can be installed on both sides of the stem. [0052] One of the cassettes 100 is horizontally situated on the port or left of the stem hull with the intake port 102 located toward the center of the watercraft 200 and to the right of the exhaust port 102. In such a configuration, a motor of the cassette 100 can drive an impeller to draw water through the intake port 102 and a pump housing and out the exhaust port 104 to propel the watercraft 200 to the right. [0053] Another cassette 100 is horizontally situated on the starboard or right of the stem hull with the intake port 102 located toward the center of the watercraft 200 and to the right of the exhaust port 104. In such a configuration, a motor of the cassette 100 can drive an impeller to draw water through the intake port 102 and a pump housing and out the exhaust port 104 to propel the watercraft 200 to the left. [0054] Other orientations and configurations for the cassettes 100 are also possible. For example, the cassettes 100 may be situated vertically and in such a configuration, the cassettes 100 will propel the watercraft 200 up or down and may help stabilize the watercraft 200 in rough water conditions. In some aspects, multiple cassettes 100 may be located on either side of the hull near the stern to provide extra propulsion. [0055] FIG. 7 is a bottom view of an embodiment of a watercraft 200 including two removable motorized cassettes, which each may be configured as the cassette 100 of FIG. 1, installed in a generally horizontal orientation on the underside of the watercraft. In this example, two motorized cassettes 100 are received in respective recesses on the bottom of a watercraft 200. [0056] As shown, the cassettes 100 are situated toward the stem of the watercraft 200 such that the intake ports 102 are located closer to the bow than the exhaust ports 104. In such a configuration, the water drawn from the intake ports 12 and out the exhaust ports 104 will produce forward propulsion for the watercraft 200. Other orientations and configurations exhaust ports 104 on the cassette 100 may be reversed, which will produce reverse or aft propulsion of the watercraft 200. Multiple cassettes 100 may be located on either side the bottom of the hull 202 to provide extra propulsion. As discussed above, the bottom cassettes 100 may provide quiet, gas saving, forward or aft propulsion. [0057] FIG. 8 is a cutaway view of the removable motorized cassette 100 of FIG. 1, illustrating a portion of the interior thereof. As shown, the cassette 100 may comprise a drive system including one or more motors 150. The one or more motors 150 can be powered through one or more wires 106 connected to the watercraft battery or other power source. In other embodiments, the one or more motors 150 can be powered by batteries housed in the cassette 100. The motor 150 can be mounted to the cassette base 101 by motor mounts 152. The motor 150 is also connected to a motor controller 155. The motor controller 155 may activate, control the speed and/or power, may deactivate, or may control other functions of the motor 150. The motor controller 155 may include a wireless receiver. This receiver can communicate with a wireless transmitter that is controlled by the driver of the watercraft in order to control the motor speed. As shown, the motor controller 155 is connected to the wires 106 which may provide power to both the motor controller 155 and the motor 150. [0058] In some embodiments, each motor 150 can be coupled to a motor shaft by a shaft coupler, shaft bearing, bearing holder, and spacer, which can be seen, for example, in FIGs. 9 and 10. Each shaft can be coupled to an impeller that is disposed at least partially within a pump housing 154 and a bearing can optionally be disposed between each shaft and the impeller. In this way, the one or more motors 150 can drive each impeller to draw water through the pump housing 154 and out the exhaust port 104 to propel the watercraft relative to a body of water. [0059] FIG. 9 is a side exploded view of some components of the removable motorized cassette 100 of FIG. 1. In particular, FIG. 9 illustrates components of the drive system of the motorized cassette 100 that are positioned within the pump housing 154 (see FIG.8) between the intake port 102 and the exhaust port 104. These components are driven by the motor 150 to accelerate water out of the exhaust port 104 to provide a propulsive force. straighter 164 are illustrated. The drive shaft 160 may be connected to the motor 150 (see FIG. 8) such that the motor 150 causes rotation of the drive shaft 160. The drive shaft 160 extends into the pump housing 154 (see FIG. 8) such that the impeller 162 and flow straightener 164 are positioned in the pump housing between the intake port 102 and the exhaust 104. The motor 150 drives the drive shaft 160 to rotate the impeller 162 which is mounted on the drive shaft 160. The drive shaft 160 can be supported by bearings 166. [0061] In some embodiments, the motor 150 may be sealed within a watertight portion of the cassette 100. A shaft cover can form a watertight seal so as to prevent water from entering inside the watertight compartment. The drive shaft 160 may be configured to through the shaft cover. The drive shaft 160 connects to the motor 150. In some embodiments, the drive shaft 160 connects to the motor 150 by being installed in a direct drive arrangement with the motor 150. In other embodiments, the drive shaft 160 connects to the motor 150 through a gear box or belt system. In some embodiments, the drive shaft 160 can contain one or more O-ring or other sealant placed on the outer half of the drive shaft. The O-ring or sealant can prevent water from entering inside the watertight compartment. Connected to the end of the drive shaft 160 is an impeller 162. The impeller 162 can be installed on the end of the drive shaft 162 through several mechanical means, including, for example, threading onto the drive shaft, bonding, welding, snap fit, or friction fit. The flow straightener 164 is installed on one end of the impeller 162. In some embodiments, the flow straightener 164 does not contact the impeller 162 when installed. In some of these embodiments, the flow straightener 164 is positioned within the within the pump housing between the intake 102 and the exhaust 104. [0062] FIG. 10 is a is a cutaway perspective view of an interior portion of an embodiment of a removable motorized cassette 100 that includes a directional exhaust attachment 180. In one aspect, an attachment 180 may be affixed to the exhaust port 104 to divert the water outflow from the exhaust port 104 outward from the watercraft 200 and thereby propelling the watercraft 200 in a lateral direction while minimizing any forward propulsion. In some aspects, the attachment 180 may comprise a removable snap-in attachment that would allow unrestricted normal thrust when removed. In some aspects, the attachment 180 may be conformable to all inside surfaces of the cassette 100 to optimize directional efficiency. In desired direction. The directional exhaust attachment 180 illustrated in FIG. 10 may be particularly useful in cassettes 100 installed on the bow of deep V hulls to effectively control the hull’s side-to- side motion. As discussed above, such a directional attachment 180 may redirect the water outflow from the exhaust port 104 to minimizing any forward propulsion and to propel the watercraft 200 in a desired direction. In some embodiments, the redirect the water from the exhaust port 104, the attachment 180 ay comprise angled or curved louvers. [0063] FIGs. 11 and 12 are perspective views of an embodiment of a dual pump motorized cassette 200. The dual pump cassette 200 can be placed within a recess 210 of a watercraft. The dual pump system 200 has a housing 201 which can hold two pump systems 800. As depicted in FIG. 12, the pump systems 800 can share a sidewall 203, which separates the pump systems into individual compartments. In some embodiments, the dual pump cassette does not have a sidewall 203 and the pump systems 800 share a single compartment. The dual pump cassette 200 can be placed within a dual recess 210.. The dual recess 210 can include two or more individual recess 211, 212, with those individual recesses 211, 212 being sized, shaped, and functionally similar to recess 204 described herein. In some embodiments, the dual pump system 200 is generally the size of the dual recess 210. In other embodiments, the dual recess 210 is slightly larger than the dual pump system so that the dual pump system 200 can be positioned within the dual recess 210 without contacting the walls of each individual recess 211, 212. In other embodiments, the dual recess 210 is a single, large space with no compartment wall 213 in-between the individual recesses 211, 212. Once installed within the dual recess 210, the housing 201 forms a watertight seal with the base so that the recess is sealed. In other embodiments, a hood is placed over the part of the housing 201 that is positioned within the dual recess 210. The hood will form a watertight seal with the pump components to prevent water from entering into the pump housing 820. Both the first and second pump systems 800 can operate independently of each other. Thus, the first pump system 800 can operate while the second pump system 800 is disabled and vice versa. Additionally, both pump systems 800 can operate simultaneously. In some embodiments, the dual pump system 200 can utilize a single exhaust port 812. In these embodiments, water received from either intake value 810 of the first and second pump system 800 is expelled out a single exhaust 202 located throughout the housing. [0064] FIGs. 13 and 14 are an exploded view and a perspective cutaway view of an embodiment of a dual pump motorized cassette 1620. When installed, the cassette 1620 connects to the base of watercraft while positioned within a recess. In one embodiment, the recess forms a tear-drop shaped aperture in the base. The tear-drop shaped aperture may be complimentary to the shapes of the insert 1614 and/or cassette 1620 such that the insert 1614 and/or cassette 1620 can be oriented and/or positioned in a desired configuration within the recess. [0065] The insert 1614 may comprise a solid or substantially ring-shaped sheet structure configured to cover at least a portion of the recess. The insert 1614 may be coupled to the recess using various coupling means, for example, adhesives, bonding agents, and/or fasteners. In some embodiments, by virtue of the complimentary shapes of the insert 1614 and the recess, the insert 1614 may be form fitted within the recess such that the engagement there between inhibits longitudinal, lateral, and/or transverse motion of the insert 1614 relative to the recess. When disposed within the recess, the insert 1614 can define a receiving space 1616 for receiving the pump system 1620. [0066] In some embodiments, the insert 1614 may include one or more protrusions 1651 configured to be inserted into one or more indentations 1659 (shown in FIG. 13) on the cassette 1620. The protrusions 1651 and indentations 1659 on the cassette 1620 can have complimentary shapes such that the protrusions may be received by the indentations by sliding the cassette 1620 forward longitudinally relative to the insert 1614. The engagement of the protrusions 1651 and corresponding indentations can result in one or more abutments that act to arrest or inhibit longitudinal, lateral, and/or transverse movement of the cassette 1620 relative to the insert 1614 and body 1600. [0067] The insert 1614 may also include a latch element 1653 that is cantilevered from a latch plate 1655. The latch element 1653 may catch one or more surfaces within a receptacle 1661 on the cassette 1620 when the cassette 1620 is received within the insert 1614 to secure the cassette 1620 in the longitudinal direction relative to the insert 1614. In this way, the cassette 1620 may be slid forward into the insert 1614 until the latch 1653 releasably secured relative to the insert 1614. To remove the cassette 1620 from the insert 1614, the latch element 1653 may be depressed by applying a force to the cantilevered end of the latch element 1653 to disengage the latch element from the notch or other feature. Disengaging the latch element 1653 then will allow a user to slide the cassette 1620 backward longitudinally relative to the insert 1614 to release the protrusions 1651 from the indentations 1659. [0068] The base surface 1622 of the pump system 1620 may be configured to substantially match the adjacent base of a watercraft to achieve a desired hydrodynamic profile. The base surface 1622 may also include a charging port 1631 and/or activation switch 1633. Thus, the cassette 1620 may be charged when the system is coupled to the watercraft or when it is separate from the watercraft. In embodiments when these are provided, the charger port 1631 can be disposed on an opposite side of the cassette 1620 and the activation switch 1633 can be disposed elsewhere as well if desired. [0069] As shown in FIGS. 13 and 14, the cassette 1620 may comprise a drive system including one or more motors 1675. In one embodiment, the drive system can be at least partially housed between a pump base 1671 and a pump cover 1657. The one or more motors 1675 can be powered by one or more batteries 1665 and can be mounted to the pump base 1671 by motor mounts 1677. In some embodiments, each motor 1675 can be coupled to a motor shaft 1690 by a shaft coupler 1679, shaft bearing 1681, bearing holder 1683, and spacer 1685. Each shaft 1690 can be coupled to an impeller 1699 that is disposed at least partially within a pump housing 1695 and a bearing 1697 can optionally be disposed between each shaft and the impeller 1699. In this way, the one or more motors 1675 can drive each impeller 1699 to draw water through the pump housing 1695 to propel the pump system relative to a body of water. [0070] In some embodiments, each shaft 1690 can be disposed within a shaft housing 1694 that is configured to limit the exposure of the shaft 1690 to objects that are separate from the pump system 1620. Thus, the shaft housing 1694 can protect a user from inadvertently contacting the shaft 1690 during use and/or can protect the shaft 1690 from contacting other objects, for example, sea grass. Additionally, the shaft housing 1694 can improve performance of the pump system 1620 by isolating each shaft 1690 from the water protected from exposure to the water by one or more shaft seals 1692. [0071] The cassette 1620 can also include one or more grates 1693 disposed over intake ports of the pump housing 1695. In some embodiments, a grate 1693 is installed over the intake ports of the pump housing 1695. The grates 1693 can limit access to the impeller 1699 and shaft 1690 to protect these components and/or to prevent a user from inadvertently contacting these components during use. In some embodiments, each pump housing 1695 and/or grate 1693 can be coupled to one or more magnetic switches (not shown) that can deactivate the motors 1675 when the pump housing 1695 and/or grate 1693 are separated from the pump base 1671. Therefore, the one or more magnetic switches may prevent the cassette from operating without the optional grate 1693 and/or pump housing in place. [0072] With continued reference to FIGS. 13 and 14, the drive system may also include one or more motor controllers 1673 for each motor 1675, one or more relays 1687 configured to connect the one or more batteries 1665 with the one or more motor controllers 1673, an antenna 1667, and a transceiver 1669. The one or more motor controllers 1673, one or more relays 1687, one or more batteries 1665, antenna 1667, and transceiver 1669, can be electrically connected to each another by one or more wiring harnesses 1663. The transceiver 1669 can include or be coupled to wireless transmission circuitry that is configured to transmit electromagnetic and/or magnetic signals underwater. [0073] Any of the features of the cassettes illustrated in FIGs. 11-14 can be included on the cassette 100 of FIG.1. [0074] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. [0075] Indeed, although this invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes of the embodiments of the disclosed invention. Any methods disclosed herein need not be performed in the order recited. Thus, it is intended that the scope of the invention herein disclosed should not be limited by the particular embodiments described above. [0076] It will be appreciated that the systems and methods of the disclosure each have several innovative aspects, no single one of which is solely responsible or required for the desirable attributes disclosed herein. The various features and processes described above may be used independently of one another or may be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of this disclosure. [0077] Certain features that are described in this specification in the context of separate embodiments also may be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment also may be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination may in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. No single feature or group of features is necessary or indispensable to each and every embodiment. [0078] It will also be appreciated that conditional language used herein, such as, among others, “can,” “could,” “might,” “may,” “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open- ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. In addition, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. In addition, the articles “a,” “an,” and “the” as used in this application and the appended claims are to be construed to mean “one or more” or “at least one” unless specified otherwise. Similarly, while operations may be depicted in the drawings in a particular order, it is to be recognized that such operations need not be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one more example processes in the form of a flowchart. However, other operations that are not depicted may be incorporated in the example methods and processes that are schematically illustrated. For example, one or more additional operations may be performed before, after, simultaneously, or between any of the illustrated operations. Additionally, the operations may be rearranged or reordered in other embodiments. In certain circumstances, multitasking and parallel processing may be advantageous. Additionally, other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve desirable results. [0079] Further, while the methods and devices described herein may be susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but, to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various implementations described and the appended claims. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with an implementation or embodiment can be used in all other implementations or embodiments set forth herein. Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein may include certain instruction of those actions, either expressly or by implication. The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like includes the number recited. Numbers preceded by a term such as “about” or “approximately” include the recited numbers and should be interpreted based on the circumstances (e.g., as accurate as reasonably possible under the circumstances, for example ±5%, ±10%, ±15%, etc.). For example, “about 3.5 mm” includes “3.5 mm.” Phrases preceded by a term such as “substantially” include the recited phrase and should be interpreted based on the circumstances (e.g., as much as reasonably possible under the circumstances). For example, “substantially constant” includes “constant.” Unless stated otherwise, all measurements are at standard conditions including temperature and pressure. [0080] As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: A, B, or C” is intended to cover: A; B; C; A and B; A and C; B and C; and A, B, and C. Conjunctive language such as the phrase “at least one of X, Y and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be at least one of X, Y or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y, and at least one of Z to each be present. The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the devices and methods disclosed herein. [0081] Accordingly, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Claims

1. A watercraft, comprising: a hull configured to float in water; at least one recess formed on the hull and extending generally inward; and at least one cassette disposed at least partially within the at least one recess, the cassette housing a drive system including at least one electric motor and at least one impeller coupled to the at least one electric motor, the cassette further comprising a water intake port and a water exhaust port, wherein the at least one cassette is disposed within the at least one recess such that the base surface of the cassette substantially matches an adjacent outer surface of the hull around the recess to form a smooth body outer surface having water intake and exhaust ports therein.

2. The watercraft of Claim 1, wherein: the at least one recess comprises a first recess positioned on a port side of the hull proximal to a bow of the hull and a second recess positioned on a starboard side of the hull proximal to the bow of the hull; and the at least one cassette comprises a first cassette disposed within the first recess and a second cassette disposed within the second recess.

3. The watercraft of Claim 2, wherein the first cassette is configured to generate a propulsive force that moves the bow of the watercraft in a starboard direction, and the second cassette is configured to generate a propulsive force that moves the bow of the watercraft in a port direction.

4. The watercraft of Claim 3, wherein each of the first and second recess are generally oriented in a horizontal position.

5. The watercraft of Claim 3, wherein each of the first and second recess are generally oriented in a vertical position.

6. The watercraft of Claim 1, wherein: the at least one recess comprises a first recess positioned on a port side of the hull proximal to a stern of the hull and a second recess positioned on a starboard side of the hull proximal to the stern of the hull; and and a second cassette disposed within the second recess.

7. The watercraft of Claim 6, wherein the first cassette is configured to generate a propulsive force that moves the stern of the watercraft in a starboard direction, and the second cassette is configured to generate a propulsive force that moves the stern of the watercraft in a port direction.

8. The watercraft of Claim 7, wherein each of the first and second recess are generally oriented in a horizontal position.

9. The watercraft of Claim 7, wherein each of the first and second recess are generally oriented in a vertical position.

10. The watercraft of Claim 1, wherein: the at least one recess comprises a first recess positioned on an underside side of the hull proximal to a stern of the hull and a second recess positioned on an underside side of the hull proximal to the stern of the hull; and the at least one cassette comprises a first cassette disposed within the first recess and a second cassette disposed within the second recess.

11. The watercraft of Claim 1, wherein the cassette comprises at least one motor controller.

12. The watercraft of Claim 1, wherein the at least one motor controller is coupled to a power source.

13. The watercraft of Claim 1, further comprising an insert disposed in the at least one recess.

14. The watercraft of Claim 13, wherein the insert comprises a protrusion and wherein at least a portion of the cassette comprises an indentation.

15. The watercraft of Claim 14, wherein at least a portion of the protrusion is at least partially received within the indentation.

16. The watercraft of Claim 15, wherein the cassette is removably coupled to the insert.