WO2024099864A1

WO2024099864A1 - Watercraft

Info

Publication number: WO2024099864A1
Application number: PCT/EP2023/080543
Authority: WO
Inventors: Jean-Claude Chauveau; Nicolas LARBOULLET; Martin Francis
Original assignee: Chauveau Jean Claude; Larboullet Nicolas; Martin Francis
Priority date: 2022-11-10
Filing date: 2023-11-02
Publication date: 2024-05-16
Also published as: FR3141925A1

Abstract

The invention relates to a watercraft comprising a hull (0) comprising a stern (1), a bow (2), and a hull bottom (3) having a stem (4) extending along a longitudinal axis (6) of the hull bottom between the bow and the stern. A propeller (5) is housed, at the stern, in a housing (8). The stem (4) is followed, towards the stern, by the housing and, between the stem and the housing, there is a water intake duct (7) leading towards the housing. The hull bottom comprises recesses respectively forming a first and a second rail (10a, 11a), a first and a second passage (12a, 13a), a first and a second symmetrical rail (10b, 11b), a first and a second symmetric passage (12b, 13b). The hull bottom comprises a screen covering the housing between a water intake opening (16a) admitting water from the water intake duct, and a water outlet opening (16b).

Description

“Boat”

TECHNICAL AREA

The present invention relates to the field of boats. Its application is particularly advantageous in the field of hull design and in particular hull design with a view to optimizing the hydrodynamic performance of the hull.

STATE OF THE ART

There are several technical solutions implementing hulls and in particular hulls having specific shapes designed in order to control the physical hydrodynamic phenomena (friction forces and pressure forces) acting on the hull and having in particular the consequences of creating resistance to the progress as well as discomfort for users. More precisely, the problems of maintaining direction and stability during tight turns can be cited in particular.

In this context, we can present the technical solution of document US7544109 which concerns a boat equipped with a recess at the stern of the boat making it possible to receive a turbine in order to limit the friction and pressure forces acting on the turbine. opposing the movement of the boat.

However, this type of solution has disadvantages and in particular the fact that it does not allow sufficient control of hydrodynamic physical phenomena.

An object of the present invention is therefore to propose a boat making it possible to overcome at least partly the disadvantages mentioned. The other objects, characteristics and advantages of the present invention will appear on examination of the following description and the accompanying drawings. It is understood that other benefits may be incorporated.

SUMMARY

To achieve this objective, according to one embodiment, a boat is provided comprising a hull comprising:

- a doll,

- a bow and

- a hull having a bow extending along a longitudinal axis of the hull between the bow and the stern, the boat further comprising a propeller housed, at the level of the stern, in a housing centered on the longitudinal axis of the hull, the bow being followed towards the stern by a recessed area in the hull forming the housing and, between the bow and the housing, a water intake conduit towards the housing, the boat being characterized in that that the hull comprises recesses, extending in the direction of the longitudinal axis, respectively forming a first rail, a second rail, a first corridor and a second corridor, the second corridor being positioned between the first corridor and the the longitudinal axis, and the second rail and the first rail being respectively positioned between the first corridor and the second corridor and in contact with the first corridor opposite the second rail relative to the first corridor, the hull further comprising recesses, by extending in the direction of the longitudinal axis, respectively forming a first symmetrical rail, a second symmetrical rail, a first symmetrical corridor and a second symmetrical corridor, the first symmetrical rail, the second symmetrical rail, the first symmetrical corridor and the second symmetrical corridor being respectively symmetrical with respect to a median plane of the hull, passing through the longitudinal axis, of the first rail, of the second rail, of the first corridor and of the second corridor and the boat being further characterized in that the hull comprises a screen covering the housing between a water inlet mouth into the housing from the water inlet conduit and a water outlet mouth outside the housing.

Thus, the presence of recesses at the level of the hull makes it possible to create zones between the surface of the water and the hull in which a mixture of water and air has the role of creating cushioning when moving forward. of the boat resulting in an increase in comfort for users who will feel less shock, particularly when the boat enters the water. The mixture in question is due to the presence of a layer of air trapped between the surface of the water and the hull as well as that of waves on which the boat advances. Added to the increase in user comfort, these recesses, due to the accumulation of the resulting air-water mixture, make it possible to limit the formation of water splashes upstream and downstream of the boat and on each side of the boat (this regardless of the condition of the surface of the water). In fact, the water, which initially would have been projected, is then trapped in the recesses, this resulting from a reduction in the friction forces acting on the surfaces of the hull and thus better maintenance of the heading and a better stability when tight turns (this particularly in rough seas or with seas presenting boat wakes), an increase in the phenomenon of sliding and propulsion (therefore leading to better propulsion efficiency and therefore increasing the speed by 20% at 30% for the same power generated), a reduction in sinking during wave descent, a reduction in the appearance time of planing for the same power generated and a reduction from 20% to 30 % of energy consumption. It is important to note that due to the configuration of the rails (concave arc shape) according to the invention, a reasonable increase in the weight of the boat results in little or no increase in fuel consumption. . The present invention also makes it possible to simplify the geometry as well as the driving of the boat, in particular by eliminating the need to position sponsons (on the jet ski in particular), fins (on surfing in particular), foils (especially when surfing, which required a significant height of water and could constitute a danger for swimmers and marine fauna) and anchors or to make adjustments (when driving). Indeed, the configuration of the hull according to the invention allows scooters in particular to make tight turns and cause less drag (compared to what sponsons allow), therefore making the use of sponsons on scooters superfluous. . In addition, the corridors act as hull stiffeners, thus having the effect of simplifying the areas occupied by heavy elements such as the engine, the fuel tank or batteries. The screen protects the propeller from friction and pressure forces coming from below the propeller, which has the effect of optimizing the operation of the propeller and therefore creating better propulsion. All of these characteristics therefore make it possible to control, in a more important and simplified manner, the physical hydrodynamic phenomena so that they have less impact on the propulsion of the boat as well as the comfort of the users.

According to another aspect, the invention relates to a boat in which the first corridor and the second corridor are respectively with the first symmetrical corridor and the second symmetrical corridor, carried, respectively, by a first V and by a second V.

This configuration makes it possible to give the hull an overall V shape, thus providing stability to the boat due to the position of the center of gravity of the boat in relation to the metacenter of the hull. Furthermore, a V-shaped hull (compared, for example, to a rectangular or rounded rectangular hull) will make it possible to achieve higher speeds for the same power generated, in particular due to the reduction in the external surface of the hull. thus making it possible to reduce the frictional forces of the water acting on the hull. According to another aspect, the invention relates to a boat in which the first rail and the second rail form circular arcs and the first corridor and the second corridor form flat surfaces.

Due to the arcuate shape of the first and second rails separated by the first and second corridors forming flat surfaces, better accumulation of the air-water mixture is achieved in the hull, thus leading to a reinforcement of the resulting technical effects. BRIEF DESCRIPTION OF THE FIGURES

The aims, objects, as well as the characteristics and advantages of the invention will emerge better from the detailed description of an embodiment of the latter which is illustrated by the following accompanying drawings in which:

Figure 1 represents electric surfing from a view facing the stern.

Figure 2 represents a cross section of the electric surfboard hull highlighting the shapes and inclinations of the corridors and rails.

Figure 3 represents the electric or thermal jet ski in a view facing the bow.

Figure 4 shows a bottom view of the electric or thermal jet ski.

Figure 5 shows a side view of the electric surfboard.

Figure 6 shows a bottom view of the electric surfboard.

Figure 7 represents the electric or thermal jet ski in a view facing the stern.

The drawings are given as examples and are not limiting to the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily on the scale of practical applications.

DETAILED DESCRIPTION

Before beginning a detailed review of embodiments of the invention, optional characteristics are set out below which may possibly be used in combination or alternatively.

According to an example, the recesses 14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h of the boat are contiguous two by two.

This configuration makes it possible to eliminate protruding areas of the hull in order to allow the corridors to direct the air-water mixture directly towards the rails without encountering obstacles.

According to one example, the first V 15a and the second V 15b define angles less than or equal to 140° and preferably greater than or equal to 80°.

Thus, these angle values make it possible to obtain the best compromise (for the same hull width) between a stable hull configuration and a shallow hull, thus making it possible to avoid damaging the hull in the event of shallow water. .

According to one example, the first V 15a defines an angle greater than an angle defined by the second V 15b.

The role of this configuration is to maintain the overall V shape of the hull.

According to one example, the water intake conduit 7 has a rectilinear shape and the bow 4 forms with the water intake conduit 7 an angle less than or equal to 20° and preferably greater than or equal to 5° .

The rectilinear shape of the water inlet conduit 7 makes it possible to constitute a progressive flow zone of the water having an inclination substantially parallel to the directions of the flow of the water subject to reaching the inlet conduit of water 7. This configuration makes it possible to reduce obstacles to the passage of water and therefore friction, which results in a limitation of the expenditure of energy to move forward.

According to one example, the screen 9 has a projecting position relative to the bow 4. This configuration is necessary to ensure that the water present at the water inlet mouth 16a can reach the propeller 5 in large quantities while having an inclination of the water inlet mouth 16a respecting the water flow lines initially present at the level of the bow 4.

According to one example, the projecting positioning of the screen 9 relative to the bow 4 is of a value less than or equal to 10 cm and preferably greater than or equal to 3 cm.

According to an example, screen 9 is flat.

Thus, this inclination has the function of limiting the pressure and friction forces acting on the areas located between the screen 9 and the bow 4.

According to one example, the screen 9 presents, at the level of the water intake mouth 16a, a concavity oriented towards the bow 4.

This concavity makes it possible to limit the pressure force of the water acting on the surface of the screen 9 presenting the concavity. Indeed, thanks to the concavity, the pressure applied will be distributed over the concave surface so that the same pressure is applied over a longer time than if the screen 9 did not present this concave surface, this resulting from a pressure felt per lesser unit of time.

According to one example, the screen 9 is joined to the hull 3, by a third rail 18a and by a third symmetrical rail 18b, extending in the direction of the longitudinal axis 6, of the water outlet mouth 16b at bow 4.

Thus, by the presence of these third rails, the air accumulating between the second rail 11 a and the second symmetrical rail 11 b cannot reach the water intake conduit 7. This configuration therefore makes it possible to prevent air circulates in the water intake conduit 7 and does not disrupt the optimal operation of the propeller.

According to one example, the boat comprises a motor and the propeller 5 is connected to the motor by a shaft 17, the motor being positioned, in contact with a part of the hull 0 not exposed to water, at the level of the junction between the bow 4 and the water intake conduit 7.

According to an example, the bow 2 has a hollow zone 19 at the level of the hull 3. This configuration makes it possible to form a water blocking zone to limit the rise of water which could have reached with significant pressure the top of the the bow 2.

The rising water in question has the effect of slowing down the boat for the same power generated.

According to one example, the first corridor 12a and the second corridor 13a have a width, defined at the water inlet mouth 16a in a direction orthogonal to the direction along the longitudinal axis 6, having a value greater than twice a width, defined at the water inlet mouth 16a in a direction orthogonal to the direction along the longitudinal axis 6, of the first rail 10a and the second rail 11a and preferably, having a value less than ten times the width of the first rail 10a and the second rail 11a and preferably the width of the second corridor 13a is greater than that of the first corridor 12a.

Thus, these different configuration possibilities make it possible to obtain configurations for which the corridors having the role of directing the air-water mixture towards the rails have widths large or smaller widths and this in comparison with the radii of the arc of the rails. In the case of configurations where the widths of the corridors are small, this results in large arc radii for the rails. This type of configuration has the effect of allowing a significant accumulation of the air-water mixture (in the rails) and therefore of obtaining significant cushioning of the shocks suffered by the boat. In the opposite case, where the widths of the corridors are large compared to those of the rails, the opposite phenomena occurs.

Furthermore, the relative choice of the width of the corridors compared to that of the rails has an influence on the stability of the hull. Indeed, a small width of corridors leads, for the same width of hull, to rails having a greater radius, which accentuates the stability due to the V shape of the hull, by creating larger hollows in the hull. .

The fact that the width of the second corridor 13a is greater than that of the first corridor 12a makes it possible to create accumulation zones of the air-water mixture close to the hull exposed to the air, which makes it possible to channel a maximum of this mixture before it creates friction forces on the hull.

According to one example, the second corridor 13a has a depth less than 8 cm and preferably greater than 0 cm and in which the first corridor 12a has a depth less than 8 cm and preferably greater than 0 cm.

Thus, these different configurations make it possible to obtain a V-shaped hull having different overall angles and different volumes of the hull (for the same overall angle) to thus define the stability of the desired hull. These different configurations also make it possible to obtain different volumes of accumulated air-water mixture and therefore to vary the desired damping. The overall angle is formed by the line joining the first rail 10a and the screen 9 with the line joining the first symmetrical rail 10b and the screen 9.

The boat developed, due to the characteristics that limit friction, makes it possible to obtain a propulsion system that limits the power generated.

It is specified that in the context of the present invention, the expression “carried by a V” relating to two planes means that the two planes are intersecting and that their intersection forms an angle different from 180° and 0°.

The term “boat” designates a sailing, rowing or motor boat of the “electric surf” type, jet-ski, boat, pleasure boat or fire boat or for fishing.

In the context of the present invention, the term “bow” designates the projecting part forming at least partly the bow of a boat. The bow extends along the lowest part of the hull towards the stern. The bow may have a V shape carried by an angle which may in particular be less than 140°. The term "low" must be taken into account by considering the usual direction of use of a water craft, the bottom being opposite the top.

According to one embodiment, as illustrated in Figure 4, the boat comprises a hull 0 comprising a stern 1, a bow 2, and a hull 3. The hull 3 has a bow 4 which extends along a longitudinal axis 6 of the hull 3 being positioned between the bow 2 and the stern 1. The boat further comprises a propeller 5 inserted, at the level of the stern 1, in a housing 8 positioned in the center of the longitudinal axis 6 of the hull 3. The bow 4 is followed towards the stern 1 by a recessed area in the hull 3 forming the housing 8 and, between the bow 4 and the housing 8 , a water intake conduit 7 towards housing 8.

The hull 3 comprises recesses 14a, 14b, 14c, 14d, extending in the direction of the longitudinal axis 6, respectively forming a first rail 10a, a second rail 11a, a first corridor 12a and a second corridor 13a . The second corridor 13a is linked to the first corridor 12a and to the longitudinal axis 6. The second rail 11a is linked to the first corridor 12a and to the second corridor 13a. The first rail 10a is linked to the first corridor 12a opposite the second rail 11a with respect to the first corridor 12a.

The hull 3 further comprises recesses 14e, 14f, 14g, 14h, extending in the direction of the longitudinal axis 6, respectively forming a first symmetrical rail 10b, a second symmetrical rail 11b, a first symmetrical corridor 12b and a second symmetrical corridor 13b. The first symmetrical rail 10b, the second symmetrical rail 11b, the first symmetrical corridor 12b and the second symmetrical corridor 13b being respectively symmetrical with respect to a plane, passing through the longitudinal axis 6, separating the hull 3 into two equal parts, of the first rail 10a, of the second rail 11a, of the first corridor 12a and of the second corridor 13a.

The hull 3 comprises a screen 9 enclosing the housing 8, on one side, between a water inlet mouth 16a into the housing 8 from the water inlet conduit 7 and a water outlet mouth 16b outside of housing 8.

Indeed, the positioning of propeller 5 in housing 8 allows the boat to be used as a rescue boat that can navigate in shallow waters, unlike current boats used by firefighters during floods.

The size of the screen 9 can be set to create a gap between the propeller 5 and the screen of 1 mm.

The length of the water intake conduit 7 can be between 20% to 35% of the total length of the boat.

The propeller 5 can be a specific propeller (but different from a turbine propeller which operates with a compression cone) which can operate while being housed in a hollow space of cylindrical shape. Its flow must be straightened by a flow rectifier.

The inlet of the water intake conduit 7 may be equipped with a grid to prevent various objects from passing through the water intake conduit 7 to reach the propeller 5.

Preferably, the recesses 14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h are separated from each other by a border having a width of at least 2 mm (for example 7 mm).

Advantageously, the first rail 10a and the second rail 11a define a rounded contour corresponding to arcs of a circle. This rounded contour can be configured so that the hollow zone defined by this contour is in contact with the water. Preferably, the first rail 10a and the second rail 11a each define a rounded (or convex) contour forming an arcuate concavity. By “element forming a concavity” is meant an element having a convex or rounded shape towards the inside. The first rail 10a and the second rail 11a can describe quarter circles with a variation of 20% to 60% of the length of the bow. Preferably, the first corridor 12a and the second corridor 13a describe flattened surfaces. The concave arcuate shape of the first rail 10a and the second rail 11a makes it possible to form an accumulation zone of the air-water mixture in the hull. This accumulation zone results in significant cushioning of the shocks suffered by the boat, resulting in better comfort for users. Also, the air-water mixture makes it easier for the hull to slide on the water, because the air microbubbles prevent a significant part of the friction of the water on the hull as it moves forward. In addition, given that the air contained in the air-water mixture remains in the rails due to their shape, the configuration of the rails according to the invention allows a better influx of water (i.e. without air) to the propulsion system.

The concave arcuate shapes of the rails 10a and 11a present respectively at the end not linked to a corridor (for the rail 10a) and at the end linked to the corridor 12a (for the rail 11a) a projecting zone having the role of effectively retaining the air-water mixture.

For electric surfing, as illustrated in Figure 2, the second corridor 13a and the second symmetrical corridor 13b can have two flat surfaces (extending in the direction of the longitudinal axis 6) connected together by a rounded surface according to the axis transverse to the longitudinal axis 6 (also extending in the direction of the longitudinal axis 6).

In an advantageous mode, the first corridor 12a and the second corridor 13a respectively describe with the first symmetrical corridor 12b and the second symmetrical corridor 13b, a first V 15a and a second V 15b.

In conjunction with the planar shape of the corridors 12a and 13a associated with the concave arcuate shape of the rails 10a and 11b, the overall V-shaped shape of the hull allows the air-water mixture (accumulated in the rails 10a and 11b ) goes up more easily towards the rails to prevent it from heading towards the propeller.

Preferably, the first V 15a and the second V 15b are characterized by angles less than or equal to 140° and preferably greater than or equal to 80°.

Advantageously, the first V 15a is characterized by an angle greater than an angle characterizing the second V 15b.

The angles of the first V 15a and the second V 15b vary depending on the position on the longitudinal axis 6. The angle of the first V 15a is smaller by 20 to 30° towards the bow 2 so that the stability of the hull is more important at the bow 2 than the stern 1.

According to a preferred embodiment, the water intake conduit 7 has an elongated shape extending along the longitudinal axis 6.

Advantageously, the bow 4 is oriented relative to the water intake conduit 7 so that the bow 4 and the water intake conduit 7 form an angle less than or equal to 20° and preferably greater than or equal to 5°.

Preferably, the screen 9 projects relative to the bow 4.

Preferably, the screen 9 protrudes relative to the bow 4 by a value less than or equal to 10 cm and preferably greater than or equal to 3 cm.

According to one possibility, the screen 9 is flat. Advantageously, the second part 9b has, at the level of the water intake mouth 16a, a concavity oriented towards the bow 4.

According to a preferred embodiment, the screen 9 is secured to the hull 3, by a third rail 18a and by a third symmetrical rail 18b, extending in the direction of the longitudinal axis 6, of the outlet mouth of water 16b at the bow 4.

Preferably, the propeller 5 is secured to a motor by a shaft 17. The motor is located, in a space formed by a part of the hull 0 not exposed to water, at the junction between the bow 4 and the water intake conduit 7.

Once in the water intake conduit 7, the water flow is oriented substantially in the same direction as the shaft 17, this in order to allow optimal operation of the propeller 5 due to the orientation of its blades.

The motor can be an electric motor and can be supplied with energy by an electric battery equipped with a variator allowing the power of the motor and the direction of rotation to be varied. The propulsion system of the boat may be a hydrojet system.

The electric motor has the advantage of limiting starting problems. The propulsion system allows the boat to circulate in very little water and to perform automatic and secure forward and reverse movements.

The electric motor can turn in both directions to simplify maneuvering.

The motor can operate at a power of 10 KW or more (for example 120 KW) so that the boat reaches a speed of 20 km/h or more (for example 70 km/h) with a autonomy of approximately 2 hours , and this in forward and reverse.

The shaft can consist of a system passing through the hull in a sealed manner and allowing its rotation.

The boat may include at the exit of the propulsion tube, that is to say at the level of the stern, a system for steering the boat, such as a rudder or a steerable tube positioned behind the propeller 5 so as to direct the flow of water (in this case, straightening the flow is not necessary).

Advantageously, the bow 2 has a hollow zone 19 at the level of the hull 3.

The hollow zone 19 can have a depth of 3 to 8 cm, the depth being defined in one direction along the longitudinal axis 6.

For the electric or thermal jet ski, as illustrated in Figures 3 and 4, the boat can include a towing ring 20.

Advantageously, the first corridor 12a and the second corridor 13a have a width, defined at the level of the water inlet mouth 16a in a direction orthogonal to the direction along the longitudinal axis 6, having a value greater than twice a width, defined at the water inlet mouth 16a in a direction orthogonal to the direction along the longitudinal axis 6, of the first rail 10a and the second rail 11a. Preferably, the width of the first corridor 12a and the second corridor 13a is less than ten times the width of the first rail 10a and the second rail 11a. In a preferred embodiment, the second corridor 13a is wider than the first corridor 12a.

For the electric or thermal jet ski illustrated in Figure 4 and for electric surfing, illustrated in Figure 6, the width of the second symmetrical rail 11 b and the second rail 11 a decreases as it approaches the bow 2. The second symmetrical rail 1 1 b and the second rail 11 a extend along the longitudinal axis 6 to a point located at a distance between 20 cm and 35 cm from the bow 2.

For the electric or thermal jet ski, illustrated in Figure 4 and for electric surfing, illustrated in Figure 6, at a distance from the bow 2 of between 25 cm and 60 cm, the first corridor 12a and the first symmetrical corridor 12b have a width which decreases as it approaches the bow 2 following the curvature of the hull 0 at the level of the bow 2. The second corridor 13a and the second symmetrical corridor 13b have a constant width from the stern 1 to the bow 2. The first rail 10a and the first symmetrical rail 10b have a width which decreases as they approach the bow 2 following the curvature of the hull 0 at the level of the bow 2. The first rail 10a and the first symmetrical rail 10b start at a distance between 60 cm and 120 cm from the bow. The first rail 10a and the first symmetrical rail 10b have a depth which increases from the bow 2 to the stern 1 and which is between 0 and 8 cm.

Regarding the electric surfboard illustrated in Figure 6, the total width of this boat can be between 60 cm and 75 cm. Its length can be between 150 cm and 300 cm. Its thickness at the front can be between 5 cm and 15 cm and at the back between 15 cm and 30 cm.

For the electric or thermal jet ski, shown schematically in Figure 4, the total width of this boat can be between 90 cm and 130 cm. The width between the second rail 11a and the second symmetrical rail 11b can be between 40 cm and 60 cm. The width of the screen 9 can be between 15 cm and 40 cm, in particular to ensure the modification of the orientation of the water flow.

In the case where the electric surfboard type boat is a rescue boat for firefighters, the boat may include a removable tow bar. The boat can also include wheels, with a diameter of 40 to 60 cm, allowing movement at a wide range of speeds, so as to reduce the time of access and launching of the boat and in particular in situations of great emergency. These wheels can be retractable when entering the water. Thus, the shell 0 can have hollowed out areas allowing the wheels to be hidden. The bars connecting the wheels can be equipped with a spring shock absorber system. The boat may also include road traffic lights. This type of configuration can also consist of a fishing boat, equipped accordingly, so as to avoid towing problems in particular.

The rescue boat may have a length of between 300 cm and 500 cm and a width of between 150 cm and 250 cm with a freeboard of 45 to 70 cm.

The boat may include a traction bar, for towing, connected to the hull 0 by a pin that can be removed. The shell material can be composite or polymers.

The invention is not limited to the embodiments previously described and extends to all the embodiments covered by the invention.

List of references

0. Shell

1. stern

2. bow

3. hull

4. bow

5. propeller

6. longitudinal axis

7. water inlet conduit

8. accommodation

9. screen

10a. first rail

10b. first symmetrical rail l la. second rail l l b. second symmetrical rail

12a. first corridor

12b. first symmetrical corridor

13a. second corridor

13b. second symmetrical corridor

14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h. recesses

15a. first V

15b. second V

16a. water inlet mouth

16b. water outlet mouth

17. tree

18a. third rail

18b. symmetrical third rail

19. hollow area

20. towing eye

Claims

1. Boat comprising a hull (0) comprising a stern (1), a bow (2), and a hull (3) having a bow (4) extending along a longitudinal axis (6) of the hull (3) between the bow (2) and the stern (1), the boat further comprising a propeller (5) housed, at the level of the stern (1), in a housing (8) centered on the longitudinal axis (6) of the hull (3), the bow (4) being followed towards the stern (1) by a recessed area in the hull (3) forming the housing (8) and, between the bow (4) and the housing (8 ), a water intake conduit (7) towards the housing (8), the hull (3) comprising recesses (14a, 14b, 14c, 14d), extending in the direction of the longitudinal axis (6), respectively forming a first rail (10a), a second rail (11a), a first corridor (12a) and a second corridor (13a), the second corridor (13a) being positioned between the first corridor (12a ) and the longitudinal axis (6), and the second rail (11a) and the first rail (10a) being respectively positioned between the first corridor (12a) and the second corridor (13a) and in contact with the first corridor (12a ) opposite the second rail (11a) relative to the first corridor (12a), the hull (3) further comprising recesses (14e, 14f, 14g, 14h), extending in the direction of the the longitudinal axis (6), respectively forming a first symmetrical rail (10b), a second symmetrical rail (11b), a first symmetrical corridor (12b) and a second symmetrical corridor (13b), the first symmetrical rail (10b), the second symmetrical rail (11 b), the first symmetrical corridor (12b) and the second symmetrical corridor (13b) being respectively symmetrical with respect to a median plane of the hull (3), passing through the longitudinal axis (6), of the first rail (10a), the second rail (11a), the first corridor (12a) and the second corridor (13a) and the hull (3) further comprising a screen (9) covering the housing (8) between a water inlet mouth (16a) into the housing (8) from the water inlet conduit (7) and a water outlet mouth (16b) outside the housing (8) characterized in that the first rail (10a) and the second rail (11a) each define a rounded contour forming an arcuate concavity and in which the first corridor (12a) and the second corridor (13a) form flat surfaces, in that the first corridor (12a) and the second corridor (13a) are respectively with the first symmetrical corridor (12b) and the second symmetrical corridor (13b), carried, respectively, by a first V (15a) and by a second V (15b) , and in that the screen (9) is flat.

2. Boat according to the preceding claim in which the first V (15a) and the second V (15b) define angles less than or equal to 140° and preferably greater than or equal to 80°.

3. Boat according to any one of the two preceding claims in which the first V (15a) defines an angle greater than an angle defined by the second V (15b).

4. Boat according to any one of the preceding claims in which the recesses (14a, 14b, 14c, 14d, 14e, 14f, 14g, 14h) are contiguous in pairs.

5. Boat according to any one of the preceding claims in which the water intake conduit (7) has a rectilinear shape and in which the bow (4) forms with the water intake conduit (7) an angle less than or equal to 20° and preferably greater than or equal to 5°.

6. Boat according to any one of the preceding claims in which the screen (9) has a projecting position relative to the bow (4).

7. Boat according to the preceding claim in which the projecting positioning of the screen (9) relative to the bow (4) is of a value less than or equal to 10 cm and preferably greater than or equal to 3 cm.

8. Boat according to any one of the preceding claims in which the screen (9) has, at the level of the water inlet mouth (16a), a concavity oriented towards the bow (4).

9. Boat according to any one of the preceding claims in which the screen (9) is joined to the hull (3), by a third rail (18a) and by a third symmetrical rail (18b), extending along the direction of the longitudinal axis (6), from the water outlet mouth (16b) to the bow (4).

10. Boat according to any one of the preceding claims comprising a motor and in which the propeller (5) is connected to the motor by a shaft (17), the motor being positioned, in contact with a part of the hull (0 ) not exposed to water, at a junction between the bow (4) and the water intake conduit (7).

11. Boat according to any one of the preceding claims in which the bow (2) has a hollow zone (19) at the level of the hull (3).

12. Boat according to any one of the preceding claims in which the first corridor (12a) and the second corridor (13a) have a width, defined at the level of the water intake mouth (16a) in an orthogonal direction to the direction along the longitudinal axis (6), having a value greater than twice a width, defined at the water inlet mouth (16a) in a direction orthogonal to the direction along the longitudinal axis (6), of the first rail (10a) and the second rail (11 a) and preferably, having a value less than ten times the width of the first rail (10a) and the second rail (11 a) and preferably the width of the second corridor (13a) is larger than that of the first corridor (12a).

13. Boat according to any one of the preceding claims in which the second corridor (13a) has a depth less than 8 cm and preferably greater than 0 cm and in which the first corridor (12a) has a depth less than 8 cm and preferably greater than 0 cm.