AU2021238497A1

AU2021238497A1 - Cover for a sea chest and method of using same

Info

Publication number: AU2021238497A1
Application number: AU2021238497A
Authority: AU
Inventors: Stuart Barrow; Zhen CHONG; Jarrod Collings; Bradley Panckhurst; Wesley van Barneveld
Original assignee: Intervention Eng Pty Ltd
Current assignee: Intervention Engineering Pty Ltd
Priority date: 2020-03-18
Filing date: 2021-03-16
Publication date: 2022-10-13
Also published as: WO2021184061A1; NO20221049A1; GB2609573B; GB202215116D0; GB2609573A; BR112022018570A2

Abstract

A cover for a sea chest water intake, the cover comprising: (a) a main body; (b) a sealing means for sealing said intake against water ingress from outside the cover; (c) a line retrieval member including a line for attachment to an anchor point located at or near the intake; wherein, in use, actuating the line retrieval member to retrieve the line moves the cover towards said intake.

Description

Cover for a sea chest and method of using same Field of the Invention

The present invention relates to a cover for a sea chest. The present invention also relates to a winch assembly for a sea chest cover. The present invention also relates to a method of fitting said cover to a sea chest.

Background of the Invention

Sea chests are water intake reservoirs in the hull of a vessel from which piping systems on the vessel draw raw water. The intakes of most sea chests are protected by gratings and/or contain baffle plates to dampen the effects of vessel speed or sea state. The size and form of the intakes often varies between vessels.

To allow full access to a sea chest, it is generally necessary to remove the water from the sea chest. At present, to remove the water from the sea chest, when the vessel is in the water the sea chest water intake is covered with a blank or cover that forms a water tight seal. These covers are generally fitted manually by divers in what is often a time consuming and often dangerous procedure.

The present invention seeks to provide a tool, an improved cover for a sea chest water intake and a method for sealing a sea chest water intake or at least provide a useful alternative to currently available tools, covers and methods.

Summary of the Invention

The present invention provides a cover for a sea chest water intake, the cover comprising:

(a) a main body;

(b) a sealing means for sealing said intake against water ingress from outside the cover;

(C) a line retrieval member including a line for attachment to an anchor point located at or near the intake; wherein, in use, actuating the line retrieval member to retrieve the line moves the cover towards said intake.

The present invention also provides a method of sealing a sea chest water intake, the method comprising the steps of:

(a) providing a cover including a sealing means for sealing said intake against water ingress from outside the cover, a line retrieval member including a line for attachment to an anchor point located at or near the intake;

(b) attaching the line to an anchor point located at or near the intake;

(c) actuating the line retrieval member to move the cover towards the sea chest water intake.

The present invention also provides a tool for a cover for a sea chest water intake, the tool comprising:

(a) a housing; and

(b) a line retrieval member, supported from said housing, for receiving a line for attachment to an anchor point located at or near the intake.

Brief Description of the Drawings

Figure 1 a is a perspective front view of a cover for a sea chest water intake according to one embodiment of the first aspect of the present invention. The cover includes a tool according to one embodiment of the third aspect of the present invention;

Figure 1b is a perspective rear view of the cover in Figure 1 a;

Figure 1c is a perspective front view of the cover in Figure 1 a including additional buoyancy members attached thereto;

Figure 2a depicts of a method of sealing a sea chest water intake according to one embodiment of a second aspect of the present invention, where the cover has been deployed from a vessel using a crane; Figure 2b depicts the method in Figure 2a, where the cover has been moved, from the position in Figure 2A, towards the sea chest water intake by actuation of the spool member;

Figure 2c depicts the method in Figures 2a and 2b, where the cover has been moved, from the position in Figure 2b, to a position adjacent to a sea chest water intake;

Figure 2d is a perspective view of the cover in Figure 1c, fitted to and sealing a sea chest water intake; and

Figure 3 depicts of a method of sealing a sea chest water intake according to another embodiment of a second aspect of the present invention that is similar to that in Figure 2b, but further includes the use of additional buoyancy on the hoisting line.

Detailed Description of the Invention

According to a first aspect, the present invention provides a cover for a sea chest water intake, the cover comprising:

(a) a main body;

The line retrieval member may be any device that is adapted to retrieve a line or otherwise adjust the tension of a line. The line retrieval member may form part of the tool according to the third aspect of the invention. The line retrieval member may be rotatable, wherein rotation of the line retrieval member retrieves the line. The line retrieval member may also be a spool member, a winder, a reel, a drum or any other device that is capable of retrieving the line or otherwise adjusting the tension of the line. The line retrieval member may comprise a gear member. Preferably, the gear member comprises at least two gears that allow the line retrieval member to operate at different torque and/or speeds. When there is more than one gear it is preferred for one gear to allow the line retrieval member to operate at higher torque and/or lower speed relative to another gear. Preferably, when there is more than one gear each gear has a different diameter to allow for operation at different torques and speeds.

The line retrieval member may be powered by a drive means, such as an electric, hydraulic or pneumatic drive or motor. Thus, the line retrieval member may further comprise a drive means.

Preferably, the line retrieval member comprises a brake means that prevents unwanted movement of the line retrieval member and/or unwanted line deployment or retrieval. Brake means include a solenoid brake, a mechanical brake and a ratchet and pawl.

Preferably, the line retrieval member is adapted to and/or can be set to freely deploy the line, with little or no drag.

The line retrieval member may be located on an outer surface of the main body. Preferably, the line retrieval member is located on the side of the main body opposite to the side of the main body upon which the sealing means is located. Alternatively, when the attachment point is located inside the seal formed between the cover and the sea chest water intake, when in use, the line retrieval member may be located on the inner surface of the cover that faces inwards when the cover is fitted.

Preferably, the line retrieval member is supported in a housing. In this regard, the line retrieval member may be in the form of a tool according to the third aspect of the invention.

The housing may fully surround the line retrieval member.

The housing may be water-tight.

Preferably, the housing is located on the main body. The housing may be integral with the main body or may comprise a separate component or tool, as per the third aspect of the invention, adapted to be attached to the main body.

When separate, the housing may be adapted to be attached to the outer surface of the cover that faces outwards when the cover is fitted or to an inner surface of the cover that faces inwards when the cover is fitted.

The housing may further comprise an outlet for the line or a plurality of outlets, when there is a plurality of lines, wherein each outlet allows for the line to be deployed from the line retrieval member to the outside of the cover.

Preferably, the outlet is a conduit or a line guide in a portion of the housing.

The outlet may further comprise a snatch block or pulley arrangement for the line.

Preferably, the outlet allows for the line to extend from the spool member to the anchor point.

Preferably, the outlet extends through a cover attachment means for facilitating the attachment of the cover to the sea chest water intake.

Preferably, the cover comprises a plurality of line retrieval members. Thus, the cover may comprise a first line retrieval member and one or more of a second line retrieval member, a third line retrieval member and a fourth line retrieval member. Preferably, the cover comprises first, second, third and fourth line retrieval members.

When there is a plurality of line retrieval members, each line retrieval member comprises a line for attachment to a respective anchor point located at or near the sea chest water intake. Thus, the present invention also provides a cover for a sea chest water intake, the cover comprising:

(a) a main body;

(b) a sealing means for sealing said intake against water ingress from outside the cover; (c) a first line retrieval member, including a first line for attachment to a first anchor point located at or near said intake, said first line retrieval member being adapted to retrieve the first line;

(d) a second line retrieval member, including a second line for attachment to a second anchor point located at or near said intake, said second line retrieval member being adapted to retrieve the second line;

(e) a third line retrieval member including a third line for attachment to a third anchor point located at or near said intake, said third line retrieval member being adapted to retrieve the third line; and

(f) a fourth line retrieval member, including a fourth line for attachment to a fourth anchor point located at or near said intake, said fourth line retrieval member being adapted to retrieve the fourth line; wherein, in use, actuating at least one of said line retrieval members to retrieve a said line moves the cover towards said intake.

It will be appreciated that when there is more than one line retrieval member selective actuation of the line retrieval members allows for the movement of the cover to be controlled in up to three dimensions.

Preferably, when there is a plurality of line retrieval members, each line retrieval member is spaced equidistantly.

Preferably, when there is a plurality of line retrieval members, each line retrieval member is located adjacent to another.

Preferably, when there are four line retrieval members, the line retrieval members are positioned to form two rows, each row having two line retrieval members.

The line may be formed from any material with suitable physical characteristics such as strength. Examples of material from which the line may be formed include: wire rope, Dyneema™, Aramid and Kevlar.

Preferably, the line is adapted to be attached to the anchor point located at or near the sea chest water intake. Preferably, the line comprises a first end adapted to be attached to the anchor point. Preferably the first end of the line further comprises an anchor member.

Preferably, the anchor member is adapted to releasably attach to the anchor point. Preferably, the anchor member is magnetic.

Preferably, the anchor member is a clamp member, hook, toggle or some other friction fitting or abutment member. Such an anchor member is useful to attach to a part of the sea chest water intake such as a grill, a surround, a coaming, a frame or a part of a hull in which the sea chest water intake is located.

The anchor member may also be adjustable. For example, it may have at least two settings or orientations - one of which allows the anchor member to attach to the anchor point and one at which the anchor member cannot attach to the anchor point. One example of an adjustable anchor member is a toggle that can be oriented to attach or detach from an anchor point, such as an eyelet or aperture.

Preferably, the line is adapted to be attached to the line retrieval member such that it can be deployed from or retrieved to the line retrieval member.

Preferably, the line comprises a second end adapted to be attached to the line retrieval member.

The sealing means may be a seal or gasket formed of elastomeric material. Preferably, the seal or gasket is formed of rubber. The seal or gasket may be resiliently flexible.

Preferably, the sealing means is formed as a continuous strip of material. Preferably, the strip of material is deformable.

The sealing means may be located on the main body so that in use, it contacts and forms a seal with a part of the sea chest water intake. Preferably, said part is a coaming or frame portion or some other part of the intake such as a surrounding portion of the intake. When said part is the coaming it may be a leading edge of the coaming. The sealing means may be located on the main body so that in use, it contacts and forms a seal with a part of a hull adjacent to the sea chest water intake. Preferably, said part is adjacent to the outside perimeter of said intake.

Preferably, the sealing means is supported from a part of the main body such as base portion thereof.

Preferably, the sealing means extends around the entirety of an outer edge surface of the base portion.

Preferably, the sealing means is adapted to form a seal under water pressure from water surrounding the vessel in which the sea chest water intake is located.

Preferably, the anchor point is a part of the sea chest water intake. In this regard, the anchor point may be one or more of a grill, a surround, a coaming or a frame that form part of the sea chest water intake.

The anchor point may also be a point inside a sea chest such as a section of the inner wall of a sea chest located adjacent to said intake.

The anchor point may also be a tab, frame or fixture attached to or mounted on the sea chest water intake or a part of the vessel hull adjacent to said intake.

The main body may comprise a housing. Preferably, the housing includes a base and a generally box shaped frame with two sides a top and a bottom.

To allow for a more positive engagement and/or stronger seal between the cover and the sea chest water intake, the cover may further comprise a cover attachment means.

Preferably, the cover attachment means comprises at least one attachment tab supported on the cover.

Preferably, the attachment tab is supported from the main body of the cover such as the housing. In one particular form of the invention the attachment tab is supported from the sides of the housing.

Preferably, the attachment tabs are located on the main body so that when the cover is fitted to the sea chest water intake, said tabs are positioned to be able to engage with at least one anchor point at or near the sea chest water intake. When so positioned the attachment tabs may be fixed to the at least one anchor point with a suitable fixing.

The cover may further comprise a locating means to assist with correctly positioning the cover on the sea chest water intake to ensure the cover forms the required seal with said intake.

Preferably, the locating means is supported from the base of the housing.

Preferably the locating means centralises the cover on the sea chest water intake.

Preferably, the locating means is adjustable to suit different sea chest water intakes.

Preferably, the locating means comprises an abutment member that is shaped and positioned to centralise the cover on the sea chest water intake by engaging at least one surface of the sea chest water intake. Even more preferably the locating means engages with or abuts a surface of a sea chest water intake surround, such as an inside surface of said intake surround.

Preferably, the locating means is a frame member with a plurality of struts or cross members.

The cover may further comprise at least one attachment point for a lifting means to allow the cover to be lifted and/or deployed.

Preferably the cover comprises two, three or four attachment points. When there is more than one attachment point the cover can be suspended on different length lines and “tilted” to suit different sea chest water intakes - as these are not always vertical/horizontal

Preferably, said attachment point is a tab, eyelet or some other suitable part that allows for a line from a lifting means to be releasably attached to the cover.

Preferably, the attachment point is located at or near an outer edge of the cover.

The cover may further comprise a buoyancy member to ease the handling of the cover when in use, such as underwater. Preferably, the buoyancy member can be releasably attached to the main body such as through the use of threaded fixings such as bolts.

Preferably, there is a plurality of buoyancy members.

When used, the buoyancy members may assist with correctly aligning the cover to the sea chest water intake.

According to a second aspect the present invention also provides a method of sealing a sea chest water intake, the method comprising the steps of:

(b) attaching the line to an anchor point located at or near the intake;

Preferably, the step of providing a cover comprises the step of attaching the cover to a lifting means such as a crane.

Preferably, the crane is located topside.

The crane may be located on the vessel including the sea chest water intake or a separate vessel or workboat.

Preferably, the method further comprises the step of lifting the cover from a vessel and deploying it over the side of a vessel.

Preferably, the lifting means further comprises a hoisting line and the method further comprises the step of deploying the hoisting line. Preferably, the hoisting line is deployed simultaneously with the retrieval of the line or retrieved simultaneously with the deployment of the line.

Preferably, the cover is a cover according to the first aspect of the invention.

Preferably, the step of attaching the line to an anchor point is performed manually. Preferably, the step of attaching the line to an anchor point is performed using a ROV.

Preferably, the step of attaching the line to an anchor point comprises the step of releasably attaching the line to the anchor point.

Preferably, the step of attaching the line to an anchor point comprises the step of attaching a fixing member between the cover and the anchor point to reinforce or strengthen the seal between the cover and the sea chest water intake.

Preferably, the step of actuating the line retrieval member comprises actuating the line retrieval member at two or more speeds or torques.

Preferably, when the line retrieval member is actuated at two or more speeds it is actuated at a higher torque/lower speed when the cover is located proximal to the sea chest water intake.

Preferably, the method further comprises the step of attaching a locating means to the cover.

Preferably, the method further comprises the step of engaging the cover with the sea chest water intake.

Preferably, the step of engaging the cover with the sea chest water intake comprises forming a seal therebetween.

According to a third aspect, the present invention provides a tool for a cover for a sea chest water intake, the tool comprising:

(a) a housing; and

Preferably, the tool comprises a plurality of line retrieval members.

Preferably, the housing further comprises an outlet for the line or a plurality of outlets, when there is a plurality of lines, wherein each outlet allows for the line to be deployed from the reel to the outside of the cover. Preferably, the outlet is a conduit or a line guide in a portion of the housing.

Preferably, the housing further comprises a buoyancy member.

Preferably, the buoyancy member can be releasably attached to the housing such as through the use of threaded fixings such as bolts.

Preferably, there is a plurality of buoyancy members.

Preferably, the tool further comprises a mounting means for attaching the tool to the cover.

Preferably, the mounting means is for removably attaching the tool to the cover. Preferably, the mounting means comprises a threaded fixing member.

Advantages

Whilst not limited to the following applicant believes the present invention has a number of advantages including one or more of the following:

(a) minimise risk by eliminating or reducing the need for divers, which

(i) increases personnel safety;

(ii) enables work in hot/cold or polluted environments;

(iii) allows work in otherwise hazardous conditions such as

• When near adjacent operational intakes

• when thrusters are in operation

• When full isolations are difficult to achieve

(iv) reduces isolation requirements (as above)

(v) reduces personnel/manning requirements

(b) speed/efficiency of installation

(c) tolerance of ocean conditions including currents and waves

(d) tolerance of vessel motion

General

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. The invention includes all such variation and modifications. The invention also includes all of the steps and features referred to or indicated in the specification, individually or collectively and any and all combinations or any two or more of the steps or features.

Each document, reference, patent application or patent cited in this text is expressly incorporated herein in their entirety by reference, which means that it should be read and considered by the reader as part of this text. That the document, reference, patent application or patent cited in this text is not repeated in this text is merely for reasons of conciseness. None of the cited material or the information contained in that material should, however be understood to be common general knowledge.

The present invention is not to be limited in scope by any of the specific embodiments described herein. These embodiments are intended for the purpose of exemplification only. Functionally equivalent products and methods are clearly within the scope of the invention as described herein.

The invention described herein may include one or more range of values (e.g. size etc). A range of values will be understood to include all values within the range, including the values defining the range, and values adjacent to the range which lead to the same or substantially the same outcome as the values immediately adjacent to that value which defines the boundary to the range.

Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Other definitions for selected terms used herein may be found within the detailed description of the invention and apply throughout. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the invention belongs.

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. In the various Figures the same reference numerals have been used to identify similar elements.

Detailed Description of the Preferred Embodiments

An embodiment of the first aspect of the present invention is a cover for a sea chest water intake generally indicated by the numeral 10, in Figures 1 a-c. The cover 10 includes a main body in the form of a housing 12 that includes a base 14 and a generally box shaped frame with two sides 16, 18, a top 20 and a bottom 22.

The base 14 includes a rectangular central plate 24 surrounded by a sealing means in the form of a seal 26 formed from a suitable material such as rubber or some other elastomeric material or resiliently flexible material with suitable strength and elastic properties, that extends around the perimeter of the central plate 24.

Supported from the central plate 24 is a locating means in the form of a frame 27 comprised of two pairs of opposed vertical 28a, 28b and horizontal 30a, 30b struts. The frame 27 is sized relative to the dimensions of the sea chest water intake 60 (see Figure 2d) to ensure that when the cover 10 is engaged with the sea chest water intake 60 the seal 26 contacts a sealing surface on the sea chest water intake 60. In this embodiment the sealing surface on the sea chest water intake 60 is the leading edge 62 of the sea chest water intake surround, in the form of frame 64 (best shown in Figure 2c).

The cover 10 includes a line retrieval member in the form of four winch reels 32a, 32b, 32c and 32d. Each winch reel 32a-d has its own drive means in the form of electric motors 34a-d. Each winch reel 32a-d has a first 36 and a second 38 section with different diameters. The larger diameter gear of the first section 36 offers higher torque/lower speed relative to the smaller diameter gear of the second section 38. The winch reels 32a-d are adapted to receive the line (not shown) formed of any material that tolerates the minimum bend radius of the winch reels. Preferably it will be strong, low friction (for the guide/conduit) and moisture tolerant. Aramid or Kevlar braided line may be used. Braided line may be preferred as it does not twist or rotate as tension is applied. To ensure line retrieved onto the winch reels 32a-d is optimally located each winch reel 32a-d further comprises a line feeding means in the form of line feeder that includes a moving part 33a-d mounted on rails 35a-d so that it can move up and down on the rails 35a-d and direct the line onto the winch reels 32a-d during retrieval.

The winch reels 32a-d and related components discussed immediately above are formed into an embodiment of a tool according to a third aspect of the present invention. Namely a tool or sub-frame 40 that includes two side portions 42a, 42b and upper and lower cross members 44a, 44b. The sub-frame 40 can be attached by threaded fixings in the form of bolts to the housing 12.

The line (not shown) from each winch reel 32a-d passes through the line feeder and then the side portions 42a, 42b of the subframe 40 via a respective conduit therein in the form of guide lines 46a-d that in turn pass through a cover attachment means in the form of attachment tabs 48a-d attached to sides 16 and 18 of the housing 12.

When the cover 10 is fitted to the sea chest water intake 60, attachment tabs 48a-d align with anchor points at or near the sea chest water intake in the form of anchor tabs or points 66a-d on the sea chest water intake frame 64 (see Figure 2c). Each anchor tab 66a-d includes an aperture through which the guide lines 46a-d and the lines (not shown) pass. When the lines (not shown) pass through said apertures they can be anchored thereto by a suitable anchor member such as an abutment means in the form of a toggle (not shown) located at or near the end of each line that is sized and/or shaped so as not to unintentionally pass through the aperture. Preferably, the toggle (not shown) is such that in one orientation it can pass through the aperture and in another orientation it cannot.

Figure 1 c shows the cover 10 of Figure 1 a but further comprising a buoyancy member in the form of a pair of floats 41 a, 41 b that are bolted to the sides 42a, 42b of the subframe 40.

A method according to one embodiment of a second aspect of the present invention will now be described with reference to Figures 2a-2d and 3. For consistency, when parts of the cover described above in relation to Figures 1a-1c, are described below, the same reference numerals are used. Figure 2a shows a cover 10 being deployed from a lifting means in the form of a crane 70 on a vessel with hull 72. The cover 10 is to be fitted to a sea chest water intake 60 located in a lower portion of the hull 72 and is attached to the crane 70 via a hoisting line 74 attached to the cover 10 via a pair of attachment points for a lifting means in the form of tabs 76a, 76b on the top 20 of the housing 12. The hoisting line 74 can be attached to the cover 10 on the deck of the vessel.

The cover 10 includes four winch reels 32a-d with lines 48a-d that pass through guide lines 46a-d and are attached to anchor points located at or near the intake in the form of tabs or points 66a-d on the sea chest water intake frame 64. The lines 48a-d can be attached to the tabs 66a-d by any suitable means such as manually by a diver or by a ROV. The free ends of lines 48a-d are attached to the tabs 66a-d using anchor members in the form of toggles (not shown) that is sized and/or shaped so as not to unintentionally pass through the aperture in the tabs 66a-d.

Once the free ends of the lines 48a-d are attached to the tables 66a-d operation of the winch reels, such as by remote operation, to retrieve the lines 48a-d results in the movement of the cover 10 towards the sea chest water intake 60. Figure 2b shows the movement of the cover 10 towards the intake 60, relative to the location of the cover in Figure 2a.

Following further retrieval of lines 48a-d, Figure 2c shows the position of the cover 10 adjacent to the intake 60. At or near the point where the cover 10 is located in Figure 2c, the gearing of the winch reels 32a-d is adjusted to high torque, low speed to provide additional control of the movement of the cover 10 into sealing engagement with the intake 60. It will be appreciated that differential retrieval of the lines 48a-d allows for a high degree of control of the movement of the cover 10.

Following further retrieval of lines 48a-d and as the cover 10 contacts the intake 60, the frame 27 contacts the edges of the frame 64 and ensures that the cover 10 locates on the intake 60 such that the seal 26 contacts the leading edge 62 of the frame 64. Figure 2d shows the cover 10 fitted to and sealing the intake 60.

Once in position, as shown on Figure 2d, additional fixings can be used to reinforce or strengthen the connection and seal between cover 10 and the intake 60 by using bolts or some other threaded fixing. Alternatively, the lines 48a-d can be relied upon in isolation. In this regard water pressure acting on the cover will tend to keep the cover 10 in place, particularly once water inside the sea chest is removed, allowing for convenient inspection of the sea chest, and the external water pressure acting on the cover 10 increases.

Removal of the cover 10 from the intake 60 and its retrieval topside is essentially a combination of the same steps for fitting the cover 10, but in reverse. Before the cover 10 is removed it would be usual for the sea chest to be filled with water to reduce the external pressure on the cover 10.

Figure 3 shows the cover 10 from earlier figures in use but incorporating a buoyancy device in the form of float 80 on the hoisting line 74. The use of the float 80 reduces the weight of the hoisting line 74 making it easier to manoeuvre and move the cover 10

Claims

1 . A cover for a sea chest water intake, the cover comprising:

(a) a main body;

2. A cover according to claim 1 wherein the line retrieval member is rotatable, wherein rotation of the line retrieval member retrieves the line.

3. A cover according to claim 1 or 2 wherein the line retrieval member is a spool member, a winder, a reel or a drum.

4. A cover member according to any one of the preceding claims wherein the line retrieval member comprises a gear member.

5. A cover according to claim 4 wherein the gear member comprises at least two gears that allow the line retrieval member to operate at different torque and/or speeds.

6. A cover according to any one of the preceding claims wherein the line retrieval member further comprises a drive means.

7. A cover according to any one of the preceding claims wherein the line retrieval member further comprises a brake means.

8. A cover according to any one of the preceding claims wherein the line retrieval member is located on an outer surface of the main body.

9. A cover according to claim 8 wherein the line retrieval member is located on the side of the main body opposite to the side of the main body upon which the sealing means is located.

10. A cover according to any one of claims 1 to 7 wherein the line retrieval member is located on the inner surface of the cover that faces inwards when the cover is fitted.

11. A cover according to any one of the preceding claims wherein the line retrieval member is supported in a housing.

12. A cover according to claim 11 wherein the housing further comprises an outlet for the line.

13. A cover according to claim 12 wherein the outlet is a conduit or a line guide in a portion of the housing.

14. A cover according to claim 12 or 13 wherein the outlet allows for the line to extend from the line retrieval member to the anchor point.

15. A cover according to any one of the preceding claims wherein the cover comprises a plurality of line retrieval members.

16. A cover according to any one of the preceding claims wherein the line is formed from a material selected from the group consisting of: wire rope and fibre rope such as Aramid, Dyneema™ or Kevlar.

17. A cover according to any one of the preceding claims wherein the line is adapted to be attached to the anchor point located at or near the sea chest water intake.

18. A cover according to any one of the preceding claims wherein the line comprises a first end adapted to be attached to the anchor point.

19. A cover according to claim 18 wherein the first end of the line further comprises an anchor member.

20. A cover according to claim 19 wherein the anchor member is adapted to releasably attach to the anchor point.

21. A cover according to claim 19 or 20 wherein the anchor member is a clamp member, magnet, hook, toggle or some other friction fitting or abutment member.

22. A cover according to any one of claims 19 to 21 wherein the anchor member is adapted to attach to a part of the sea chest water intake such as a grill, a surround, a coaming, a frame or a part of a hull in which the sea chest water intake is located.

23. A cover according to any one claims 19 to 22 wherein the anchor member is adjustable.

24. A cover according to claim 23 wherein the anchor member has at least two settings or orientations - one of which allows the anchor member to attach to the anchor point and one at which the anchor member cannot attach to the anchor point.

25. A cover according to any one of claims 19 to 24 wherein the anchor member is a toggle that can be oriented to attach or detach from an anchor point, such as an eyelet or aperture.

26. A cover according to any one of the preceding claims wherein the line comprises a second end adapted to be attached to the line retrieval member.

27. A cover according to any one of the preceding claims wherein the sealing means is a seal or gasket formed of elastomeric material.

28. A cover according to any one of the preceding claims wherein the sealing means is formed from a number of sections joined together.

29. A cover according to any one of the preceding claims wherein the sealing means is located on the main body so that in use, it contacts and forms a seal with a part of the sea chest water intake.

30. A cover according to claim 29 wherein said part is a coaming or frame portion of the intake such as a surrounding portion of the intake.

31 .A cover according to claim wherein said part is a leading edge of the coaming.

32. A cover according to any one of the preceding claims wherein the sealing means is located on the main body so that in use, it contacts and forms a seal with a part of a hull adjacent to the sea chest water intake.

33. A cover according to claim 32 wherein said part is adjacent to the outside perimeter of said intake.

34. A cover according to any one of the preceding claims wherein the sealing means is adapted to form a seal under water pressure from water surrounding the vessel in which the sea chest water intake is located.

35. A cover according to any one of the preceding claims wherein the anchor point is a part of the sea chest water intake.

36. A cover according to claim 35 wherein the anchor point is one or more of a grill, a surround, a coaming or a frame that form part of the sea chest water intake.

37. A cover according to claim 35 wherein the anchor point is a point inside a sea chest.

38. A cover according to claim 35 wherein the anchor point is a tab, frame or fixture attached to or mounted on the sea chest water intake or a part of the vessel hull adjacent to said intake.

39. A cover according to any one of the preceding claims wherein the cover further comprises a cover attachment means.

40. A cover according to claim 39 wherein the cover attachment means comprises attachment tabs located on the main body so that when the cover is fitted to the sea chest water intake, said tabs are positioned to be able to engage with at least one anchor point at or near the sea chest water intake.

41 .A cover according to any one of the preceding claims further comprising a locating means to assist with correctly positioning the cover on the sea chest water intake to ensure the cover forms the required seal with said intake.

42. A cover according to claim 41 wherein the locating means is supported from the base of the housing.

43. A cover according to claim 41 or 42 wherein the locating means centralises the cover on the sea chest water intake.

44. A cover according to any one of claim 41 to 43 wherein the locating means is adjustable to suit different sea chest water intakes.

45. A cover according to any one of claims 41 to 44 wherein the locating means comprises an abutment member that is shaped and positioned to centralise the cover on the sea chest water intake by engaging at least one surface of the sea chest water intake.

46. A cover according to any one of claims 41 to 45 wherein the locating means engages with or abuts a surface of a sea chest water intake surround, such as an inside surface of said intake surround.

47. A cover according to any one of claims 41 to 46 wherein the locating means is a frame member with a plurality of struts or cross members.

48. A cover according to any one of the preceding claims wherein the cover further comprises at least one attachment point for a lifting means to allow the cover to be lifted and/or deployed.

49. A cover according to claim 48 wherein said attachment point is a tab or an eyelet.

50. A cover according to any one of the preceding claims wherein the cover further comprises a buoyancy member.

51 .A method of sealing a sea chest water intake, the method comprising the steps of:

(a) providing a cover including a sealing means for sealing said intake against water ingress from outside the cover and a line retrieval member including a line for attachment to an anchor point located at or near the intake;

(b) attaching the line to an anchor point located at or near the intake;

52. A method according to claim 51 wherein the step of providing a cover comprises the step of attaching the cover to a lifting means such as a crane.

53. A method according to claim 51 or 52 wherein the lifting means further comprises a hoisting line and the method further comprises the step of deploying the hoisting line.

54. A method according to claim 53 wherein the hoisting line is deployed simultaneously with the retrieval of the line or retrieved simultaneously with the deployment of the line.

55. A method according to any one of claims 51 to 54 wherein the step of attaching the line to an anchor point is performed manually.

56. A method according to any one of claims 51 to 54 wherein the step of attaching the line to an anchor point is performed using a ROV.

57. A method according to any one of claims 51 to 56 wherein the step of attaching the line to an anchor point comprises the step of releasably attaching the line to the anchor point.

58. A method according to any one of claims 51 to 57 wherein the step of attaching the line to an anchor point comprises the step of attaching a fixing member between the cover and the anchor point to reinforce or strengthen the seal between the cover and the sea chest water intake.

59. A method according to any one of claims 51 to 58 wherein the step of actuating the line retrieval member comprises actuating the line retrieval member at two or more speeds or torques.

60. A method according to claim 59 wherein, when the line retrieval member is actuated at two or more speeds, it is actuated at a higher torque/lower speed when the cover is located proximal to the sea chest water intake.

61. A method according to any one of claims 51 to 60 further comprising the step of attaching a locating means to the cover.

62. A method according to any one of claims 51 to 61 further comprises the step of engaging the cover with the sea chest water intake.

63. A method according to claim 62 wherein the step of engaging the cover with the sea chest water intake comprises forming a seal therebetween.

64. A tool for a cover for a sea chest water intake, the tool comprising:

(a) a housing; and

65. A tool according to claim 64 comprising a plurality of line retrieval members.

66. A tool according to claim 64 or 65 wherein the housing further comprises an outlet for the line or a plurality of outlets, when there is a plurality of lines, wherein each outlet allows for the line to be deployed from the reel to the outside of the cover.

67. A tool according to claim 66 wherein the outlet is a conduit or a line guide in a portion of the housing.

68. A tool according to any one of claims 64 to 67 wherein the housing further comprises a buoyancy member.

69. A tool according to claim 68 wherein the buoyancy member can be releasably attached to the housing such as through the use of threaded fixings such as bolts.

70. A tool according to claim 68 or 69 wherein there is a plurality of buoyancy members.

71 .A tool according to anyone of claims 64 to 70 further comprising a mounting means for attaching the tool to the cover.

72. A tool according to claim 71 wherein the mounting means is for removably attaching the tool to the cover.

73. A tool according to claim 71 or 72 wherein the mounting means comprises a threaded fixing member.