This invention relates to a system for suspending structures in a boat and/or recovering energy from moving masses in a boat. The boat may be any form of aquatic vehicle.

Motion sickness is a sensation sometimes experienced when travelling by boat, car, train or plane. The sensation can be particularly acute when travelling on a boat at sea due to the motion of the waves. Present treatments for motion sickness include pharmaceuticals. They may cause drowsiness and render the user unable to operate a boat or complete other operations onboard.

Maritime transport makes up a significant proportion of global freight. Goods that are transported by boat or ship are subjected to rocking and forces caused by the waves. Fragile goods such as scientific instruments may be damaged by such forces. The cost of protective packaging or alternative means of transport can be expensive. It is desirable to have a more stable carrying deck for transporting fragile cargo by sea.

It would be desirable to reduce the motion of a region on which passengers or cargo are borne on a boat to reduce the motion sickness of passengers or to reduce the possibility of damage to cargo. The region bearing passengers or cargo will be referred to as a deck. The region with an exterior surface that is in contact with a body of water, such as a sea or lake, will be referred to as a hull.

As green technology becomes more prevalent, it is becoming increasingly important to consider electric power. Batteries are often used with renewable energy generators to store energy. Battery systems for powering a motor or machinery aboard a vessel are sensitive to vibrations and jolts caused by the waves. It would be beneficial to provide a suspension system for protecting batteries from the forces exerted on a boat.

Thus, it would be desirable to provide a suspension mechanism for reducing the motion of passengers or cargo on a boat, or of the boat’s own machinery. As will be described below, it may also be possible to capture energy in conjunction with such motion reduction. The reduction of motion may be relative to a comparable boat not equipped with such systems or relative to the hull of the boat.

SUMMARY OF THE INVENTION

According to a first aspect there is provided a boat comprising a deck and a hull, the deck being mounted to the hull so as to be moveable relative to the hull, an energy recovery mechanism extending between the deck and the hull for recovering energy from relative motion of the deck and the hull, and an extendable barrier extending between the deck and the hull for protecting a channel therebetween.

The extendable barrier may be flexible.

The extendable barrier may comprise a first part secured to the deck and a second part secured to the hull, the first and second parts being configured to slidably engage each other.

The extendable barrier may be discontinuous around the perimeter of the deck.

The extendable barrier may be configured to seal at least a portion of the perimeter of the deck to the internal side of the hull.

The extendable barrier may be configured to seal the entire perimeter of the deck to the internal side of the hull.

The extendable barrier may be permeable.

The energy recovery mechanism may be configured to damp motion of the deck relative to the hull.

The boat may further comprise a battery for storing energy generated by the energy recovery mechanism. The boat may be a rigid inflatable boat. The boat may comprise inflatable tubes on opposing sides of the boat. The extendable barrier may comprise part of the inflation tubes.

The extendable barrier may comprise part of a sidewall of each inflation tube.

The boat may further comprise a damper acting between an underside of the deck and the hull for damping the relative motion of the deck and the hull.

The damper may be coupled in parallel to the energy recovery mechanism.

The energy recovery mechanism may be a linear generator.

The extendable barrier may be thermally welded to the deck and/or the internal side of the hull.

The extendable barrier may form an edging about the perimeter of the deck.

The channel between the deck and the hull may have a variable width.

According to another aspect there is provided a boat having an energy capturing system for powering motion of the boat, the boat comprising a hull; a deck positioned within the hull; and a plurality of energy capture mechanisms coupled between the hull and the deck such that movement of the hull relative to the deck transfers kinetic energy to the energy capture mechanisms, damping motion of the deck.

According to another aspect there is provided a boat comprising: a hull; a deck positioned within the hull; and a plurality of energy capture mechanisms coupled between the hull and the deck such that movement of the hull relative to the deck transfers kinetic energy to the energy capture mechanisms, wherein the boat comprises a plurality of sensors and a control system configured to control the energy capture mechanisms in dependence on data received from the sensors. The boat may comprise a plurality of load sensors. The control system may be configured to control the energy capture mechanisms in dependence on loads sensed by the load sensors.

The sensors may be configured to monitor the state of a body of water. The sensors may comprise, for example, one or more of a LiDAR, radar, or sonar sensor.

The control system may be configured to control the energy capture mechanisms in dependence on the data so as to at least partially stabilise motion of the deck about a horizontal axis.

The deck may be planar. The horizontal axis may be in the plane of the deck.

Where the sensors are load sensors, each of the plurality of load sensors may be coupled to the deck or the hull and may be configured to sense a load on the deck or the hull at a respective position on the deck or the hull. The control system may be configured to receive data from the load sensors and process the data to determine the load on the deck or the hull at each respective position,

The plurality of energy capture mechanisms may be for powering motion of the boat.

Each energy capture mechanism may have a corresponding load sensor configured to sense the load at a position corresponding to the respective energy capture mechanism.

The boat may further comprise a battery for storing energy generated by the energy capture mechanisms. The battery may be for powering the motion of the boat.

The battery may be positioned between the hull and an underside of the deck, and the weight of the battery supported by the deck.

The boat may further comprise an engine for powering the boat and a fuel tank in fluid communication with the engine. The fuel tank may be coupled to the deck such that it is supported thereby. The fuel tank may be positioned between the hull and an underside of the deck.

The boat may further comprise dampers, the dampers acting between an underside of the deck and the hull for damping the motion transferred from the hull to the deck.

Each energy capture mechanism may have a corresponding damper. The dampers may be coupled in parallel to the energy capture mechanisms.

The control system may be configured to control the dampers in dependence on data received from the sensors.

The control system may be configured to control the dampers in dependence on loads sensed by the load sensors.

The or each energy capture mechanism may be a linear generator.

Each energy capture mechanism may have a respective compliance. The control system may be configured to control the compliance of each energy capture mechanism in dependence on the data received from the sensors. The control system may be configured to control the compliance of each energy capture mechanism in dependence on the loads sensed by the load sensors.

The boat may further comprise a plurality of accelerometers. The accelerometers may be configured to correspond with the energy capture mechanisms to stabilise the deck relative to the hull.

The plurality of accelerometers may each be configured to correspond with a respective energy capture mechanism. The control system may be configured to control the energy capture mechanisms in dependence on data received from the accelerometers to stabilise the deck relative to the hull. The boat may further comprise a plurality of load sensors and logic hardware configured to sense a payload and distribute the mass by varying the dampers to vary the suspension of the deck.

The boat may comprise a mechanism for moving a payload carried by the deck or within the hull, wherein the mechanism is configured to be driven to vary the position of the payload relative to the deck and/or the hull in dependence on one or more loads measured by the load sensors.

According to another aspect there is provided a boat comprising: a hull; a deck positioned within the hull; and a plurality of load sensors, wherein the boat comprises a mechanism for moving a payload carried by the deck or within the hull, wherein the mechanism is configured to be driven to vary the position of the payload relative to the deck and/or the hull in dependence on one or more loads measured by the load sensors.

According to another aspect there is provided a boat comprising: a hull, a deck located within the hull, a flexible edging attaching a deck to an internal side of the hull and forming a seal between the deck and hull; and a plurality of energy capture mechanisms coupled between the hull and the deck such that movement of the deck relative to the hull transfers kinetic energy to the energy capture mechanisms, wherein the energy capture mechanisms are configured to damp motion of the deck.

According to another aspect there is provided a boat comprising a hull; a deck; and an active control system for sensing loads on the hull, configured to control the energy capture mechanisms in response to the sensed loads so as to at least partially stabilise motion of the deck about a horizontal axis.

The boat may further comprise a foredeck hingedly attached to the deck.

According to a further aspect there is provided a rigid inflatable boat comprising at least one inflatable flotation tube; and at least one linear generator coupled to the inflatable tube such that compression of the tube causes kinetic energy to be transferred to the linear generator; and a drive mechanism for driving motion of the boat, the drive mechanism being electrically coupled to the linear generator to receive energy therefrom.

The rigid inflatable boat may be configured such that the linear generator is disposed internally of the flotation tube.

The linear generator may be attached between a deformable wall of the flotation tube that defines an exterior surface of the boat and a wall of the flotation tube internal to the boat.

The rigid inflatable boat may comprise an electrical energy store, the electrical energy store being electrically coupled to the linear generator to receive energy therefrom, and being electrically coupled to the drive mechanism to supply energy thereto.

According to a further aspect there is provided a rigid inflatable boat comprising a hull; a deck positioned within the hull; and a plurality of energy capture mechanisms coupled between the hull and the deck such that movement of the hull relative to the deck transfers kinetic energy to the energy capture mechanisms; at least one inflatable floatation tube.

The at least one inflatable floatation tube may comprise a compliant inner surface disposed between the deck and hull for enclosing the energy capture mechanisms.

According to another aspect there is provided a boat comprising a hull, a deck suspended over at least part of the hull and spaced from the hull so as to define a channel therebetween, a flexible strip bridging at least part of the channel, and an inflatable tube wall wrapping over the exterior of the flexible strip and defining an inflatable volume between the strip and the wall for enhancing the buoyancy of the boat. There may be one or more generators coupled between the hull and the deck. The or each such generator may be inboard of the flexible strip.

The boat may be configured to carry one or more masses, wherein the one or more masses are supported by the deck. At least one of the one or more masses may be attached to the deck. DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example with reference to the accompanying drawings. In the drawings:

Figure 1 shows a boat with a suspended hull and energy capture mechanisms.

Figure 2 shows a boat with a mass hung from a suspended deck.

Figure 3a shows a plan view of a boat with linear generators coupled between the hull and deck and an extendable barrier extending between the deck and the hull.

Figure 3b shows a cross-sectional view of the boat of Figure 3(a) with linear generators coupled between the hull and deck and an extendable barrier extending between the deck and the hull.

Figure 4 shows a boat with a suspended hull, hinged foredeck and seal.

Figure 5 shows a cross section of a boat with a hinged foredeck and slidable cover.

Figure 6 shows a rigid inflatable boat with an energy generating system.

Figure 7a shows a cross section of a rigid inflatable boat with a flexible element between the deck and hull.

Figure 7b shows a cross-section of a rigid inflatable boat with a flexible element between a RIB side tube and deck.

Figure 7c shows a cross-section of a rigid inflatable boat with a flexible element connected between the deck, RIB side tube and hull. DETAILED DESCRIPTION

The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art.

The general principles defined herein may be applied to other embodiments and applications without departing from the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

The present invention relates to an energy recovery system for a boat. Energy is captured from the motion of the boat caused by riding through water and experiencing the forces exerted by the water. As the boat pitches, rolls and heaves, linear generators convert this kinetic energy from motion into electrical energy. The electrical energy may be used to power the boat, or may be stored, for example in a battery.

Figure 1 shows a boat 100 with a hull 101 . The boat has a deck 102, the deck is within the hull. The deck may have seats. The deck may be within the inner perimeter of the hull, it may occupy the whole of hull or part of the hull. The deck may be flat or non-planar. The deck may extend laterally outside the periphery of the hull or it may be entirely within the periphery of the hull. In this example, the deck 102 is suspended above the floor of the hull 101. The deck 102 may be a platform. The deck can be flat. The deck can support occupants of the boat and/or cargo. The deck may be flexible, for example the deck may be inflatable.

Figure 1 shows a boat comprising a plurality of energy capture mechanisms 103. The energy capture mechanisms 103 may be or comprise a generator such as a linear generator. The energy capture mechanism could generate electrical energy or another form of energy. The mechanism could comprise hydraulic pistons or pneumatic pistons which could pressurise a fluid in an accumulator for later use. The energy capture mechanism is suitable for stabilising the deck 102 relative to the hull 101. In this example the generators are linear generators. Each linear generator 103 is coupled between the hull 101 and the deck 102 of the boat. The linear generator may comprise a connecting portion for removably attaching to the hull. The linear generator may further comprise a second connecting portion for removably attaching to the deck. A battery 104 is shown suspended from the deck 102. The linear generators 103 may have electrical connections for transmitting electricity to the battery 104. A mass 105 is shown supported by the deck 102. This mass may be a cargo loaded onto the boat, a fuel tank, it may be human occupants of the boat or any other load. The boat may also comprise a plurality of sensors 108. In this example, the sensors are load sensors. The load sensors may be located at various positions on the deck and/or the hull. The boat may also comprise a control system 109 for controlling the linear generators. The control system may be configured to receive data from the load sensors 108.

The load may be mounted on top of the deck and/or attached below the deck in the volume enclosed by the hull. In either case, the load may be attached so as to move with the deck.

The deck 102 is not fixed rigidly to the hull 101 , rather the deck is mobile relative to the hull. The plurality of linear generators 103 are coupled between the hull and the deck such that movement of the hull relative to the deck transfers kinetic energy to the linear generators. The linear generators 103 are configured to damp motion of the deck 102. When the hull moves, for example because of a force exerted by a wave, it exerts a force on the deck. At least some of that force is absorbed in motion of the linear generators. As a result, the deck moves less than it would if there were a rigid connection between the deck and the hull. Mechanically, the deck is treated as a ground, and the motion system helps to reduce absolute motion of the deck under the influence of the hull, especially in directions not associated with the primary motion of the boat. Those directions include pitch, roll and heave.

Put another way, the deck is suspended relative to the hull by a suspension mechanism which supports the deck and transmits the weight of the deck and any load carried by the deck to the hull, but also permits relative motion of the hull and the deck. The generator(s) are coupled to the suspension mechanism so that motion of the suspension mechanism, such as expansion or contraction of a supporting strut of the suspension mechanism, can cause energy to be captured by the generator(s). The supporting strut(s) could for example comprise spring and damper arrangements or pressurised balloons. The generator(s) could act as dampers. As will be described further below, a spring component of the supporting strut could be integrated with a side tube structure of a rigid inflatable boat. The generators could be linear-acting generators or could capture energy through motion other than linear motion: for example, through flexing of a joint.

Figure 2 shows a boat 200 having a hull 201 and a deck 202. A plurality of linear generators 203 are coupled between the deck 202 and hull 201 . A mass 204 is supported by the deck 202, the mass 204 may comprise equipment for driving the boat, for example any one or more of a motor, a battery, an engine, a gearbox and a fuel tank. The mass 204 may comprise a control system 209 for controlling the linear generators. A foredeck 205 is movably attached to the deck 202. The foredeck may be attached to the deck using a hinge 206. The deck 202 is attached to an internal side of the hull 201 by a flexible edging 207. The flexible edging 207 forms a seal between the deck and hull. The flexible edging may extend around the entire perimeter of the deck 202. The boat may also comprise a plurality of sensors 208, for example load sensors. The load sensors may be located at various positions on the deck and/or the hull.

Figure 3a shows a top-down view of a boat. Figure 3b shows a cross-sectional view of the boat. The boat comprises a hull 301 and a deck 302. Below the deck 302, linear generators 303 are shown. A mass 304 is also shown, this may be a battery or a fuel tank.

A boat without a hinged foredeck could comprise a flexible strip or edging 305, which may in some implementations form a seal between the perimeter of a deck and inner perimeter of a hull. The edging 305 that connects the deck and the hull can act as a barrier to protect a channel between the deck and the hull, as will be described in more detail below. The barrier can serve as a protective surface to isolate the moving elements from occupants of the boat. Figure 4 shows a top-down view of the boat shown in figure 2. The boat comprises a hull 401 and a deck 402. Below the deck 402, linear generators 403 are shown. A foredeck 404 at the prow of the boat is shown. The foredeck 404 may be hinged and attached to the deck 402. The foredeck may have linear generators coupled beneath it to the hull (not shown). A flexible edging 405 is disposed between the hull 401 and deck 402.

The hinged foredeck may be fitted with a sliding element that covers the hinge between the foredeck and deck. This is described in Figure 5.

Figure 5 shows a cross section of a boat with a hull 501 , a deck 502, a hinged foredeck 504 and a slidable cover 503. The slidable cover 503 may be attached to the foredeck with an attachment 505. The slidable cover protects and covers the hinged joint between the deck and foredeck.

As mentioned above, a boat (with or without a hinged foredeck), may comprise a flexible edging or strip connecting the deck to the hull. This can act as an extendable barrier extending between the deck and the hull. The extendable barrier may form an edging about the perimeter of the deck.

The barrier may connect the deck to the internal side of the hull (the side not contacting the water in use). The deck may be disposed within the perimeter of the hull (i.e. inboard of the hull). There may be a channel between the perimeter of the deck and the hull to allow the deck to move relative to the hull. The channel between the deck and the hull may have a variable width (in a lateral direction, parallel to the plane of the deck) due to the deck and the hull being configured to move relative to one another.

The barrier may allow the deck to move relative to the hull. The barrier may allow the deck to adopt various configurations with respect to the hull when the energy recovery mechanisms undergo motion. The barrier can prevent cargo or personnel/passengers from falling into the channel between the deck and the hull or becoming trapped between the moving deck and hull, which could cause injury or malfunction of equipment below the deck. In some examples, the barrier may be configured to seal at least a portion of the perimeter of the deck to the internal side of the hull. In some cases, the barrier may be configured to seal the entire perimeter of the deck to the internal side of the hull. In other examples, the extendable barrier may be permeable and allow gas and/or liquid to penetrate the barrier.

The barrier may comprise a unitary piece of material or multiple pieces of material. The barrier may be adhered to the deck and/ or to the hull by, for example, thermal welding, an adhesive, or mechanical fixings such as staples nails or pins.

The extendable barrier may flexible. This can allow the barrier to extend and contract as the deck moves relative to the hull. For example, the barrier may be made from a fabric material. The barrier may be made from a waterproof material. The barrier may be made from an elastic material.

The barrier may be continuous around the perimeter or the deck or may be discontinuous.

The extendable barrier may comprise a first part secured to the deck and a second part secured to the hull. The first and second parts being configured to slidably engage each other. The first and second parts may be rigid, or one or more of the parts may be flexible to allow that part to conform to the shape of the other part. The parts may be resiliently biased so that one part can bear against the other. This may help to prevent items from passing between the parts into the channel.

The barrier may be extendable in a lateral direction as the deck moves relative to the hull. The barrier may be extendable between the deck and the hull in a direction parallel to the plane of the deck. In some examples, the extension may have a component that is not in the lateral direction. For example, if the barrier is attached to the hull at a position lower than the height of the deck, as shown for edging 305 in Figure 3b, the extension may have a component in a direction perpendicular to the deck. Generally, the extension of the barrier will predominantly be in a lateral direction as the hull moves relative to the deck. Figure 6 shows a rigid inflatable boat (RIB) 600. The RIB comprises an inflatable tube 601. The RIB may have a side tube that is inflatable, it may have a plurality of side tubes. The RIB has a deck 602. The deck 602 is connected to the inflatable tube 601 . Within the inflatable tube 601 there are a one or more of linear generators 603. Each linear generator may be coupled to an internal surface of the inflatable tube by a coupling 604, the coupling may be a bearing, alternatively a permanent fixing may be used such as an adhesive.

At least part of the wall of the side tube, for example a part forming an exterior surface of the boat, is flexible. As a result, the tube can deform when a force is exerted on it from outside the boat, as for instance when the boat hits a wave. That deformation can cause a linear generator coupled to the tube to extend or contract, thereby capturing energy. Conveniently the linear generator may be an electrical generator. Electrical energy captured by the linear generator may be used to drive the boat, optionally via a battery.

Figure 7a shows a section of a RIB 700. The RIB comprises a hull 701 , a deck 702, a side tube 704. The RIB comprises one or more linear generators 703. Each linear generator 703 may be coupled to the hull 701 and the deck 702 by a coupling 706, the coupling may be a bearing, alternatively a permanent fixing may be used such as an adhesive. Each linear generator 703 may be between the hull and the deck, enclosed from passengers of the boat. A compliant inner surface 705 may be disposed between the deck and hull. The compliant inner surface 705 may be a part of the side tube 704, or it may be an additional component that is fixed to the side tube. The side tube structure can be modified to assist with accommodating the relative motion between the hull 701 and deck 702. The tube inner surface 705 may also provide the function of the seal as described above in relation to figure 3. The inner tube surface 705 may provide a seal between the deck and the hull. The inner surface 705 provides an airtight seal to permit inflation of the RIB tube. The inner surface 705 may allow the deck 702 to move relative to the hull 701 .

Put another way, the deck and hull are interconnected by a flexible strip. A lower part of the flexible strip is attached to the hull, either rigidly or by a hinged joint. It may be attached at the upper rim of the hull, or lower down. An upper part of the flexible strip is attached to the deck, either rigidly or by a hinged joint. It may be attached at the outer rim of the deck, or inboard. An intermediate part of the flexible strip extends freely between the deck and the hull. Since the strip is flexible, that intermediate part permits relative motion of the deck and the hull through flexing of the intermediate part. The strip is elongate around the perimeter of the deck. A single strip may extend around the whole of the deck. Alternatively there may be multiple separate strips extending along respective parts of the edge of the deck. A generator such as a linear generator extends between the deck and the hull for capturing energy, as described above. Conveniently, the strip may bow outwardly with respect to the hull, and the linear generator may be located inboard of the strip. In that way the strip can protect the linear generator from impact from outside the boat. An inflatable tube wall is provided for increasing the buoyancy of the boat. The inflatable tube wall may envelope the intermediate part of the strip, outboard of the strip. The inflatable tube wall may be sealed to the strip along upper and lower sealing paths. In that way an inflatable volume may be provided by the strip and the inflatable tube wall in cooperation: the strip providing an inner wall of the volume and the inflatable tube wall providing the outer wall of the volume. The intermediate part of the strip may be bowed vertically into the volume. With this arrangement, flexing of the intermediate part of the strip will predominantly be in a lateral direction as the hull moves relative to the deck. On compression the strip will flex into the inflatable volume. That volume provides convenient protection for occupants against movement of the strip. The strip additionally protects occupants from the gap that could otherwise exist between the deck and the hull.

In some examples, the extendable barrier discussed above may comprise part of the inflation tubes of a RIB. The extendable barrier may comprise part of a compliant inner surface of each inflation tube of the RIB. The extendable barrier may further comprise a flexible element, as described below.

Figure 7b shows a section of an alternative example of a RIB 700. A compliant inner surface 705 is disposed between the deck 702 and hull 701 . A flexible element 707 is provided between the side tube 704 and the deck 702. The deck 702 can move relative to the hull 701 . The flexible element 707 may function to prevent passengers or cargo falling between the deck and hull. The flexible element 707 may seal only a portion of the perimeter of the deck. The flexible element may be provided along a portion of the RIB side tube. The flexible element 707 may be adhered to the deck and/or to the side tube by thermal welding, or by using an adhesive.

Figure 7c shows a section of a further example of a RIB 700. As seen, a flexible element 708 is provided between the deck 702 and a RIB side tube 704.

In a first embodiment there is provided a boat having a hull and a deck. The deck is arranged within the hull. The boat has an energy capturing system, comprising a deck positioned within a hull and a linear generator coupled between the hull and the deck such that movement of the hull relative to the deck transfers kinetic energy to the linear generator. A plurality of linear generators may be used.

When a vessel is afloat, the motion of the water, particularly wave motion when at sea, causes the hull to move. In the configuration described, there is provided a deck that is maintained in a constant position relative to the moving hull. The substantially static deck means that passengers aboard will not be subjected to repetitive motions that are likely to induce seasickness. Furthermore, fragile cargo may be safely transported when supported by the deck. The deck may be provided with stations to receive cargo, for example lockers or mounts to receive goods or seats to receive occupants. In that way the mass of the deck may be augmented, thereby increasing its inertia.

In each of the examples described herein, one or more masses carried by the boat, such as the battery, may be supported by the deck of the boat. The mass(es) may be attached to the deck so that they cannot move relative to the deck. Supporting the mass(es) carried by the boat on the deck may make the deck as close to a ground as possible relative to the hull, thereby increasing the motion of the hull relative to the deck. This will in turn increase the opportunity to harvest energy from the relative motion between hull and deck, whilst at the same time decreasing the gross movement of the deck to improve the ride comfort for passengers and reduce the vibration inputs to equipment fixed to, or being carried on, the deck.

The energy capturing system functions as a suspension system to suspend the deck away from the hull. The system may further comprise a plurality of load sensors and logic hardware configured to sense a payload on the deck and distribute the mass by varying the suspension below the deck. By varying the resistance to compression of individual dampers coupled to the linear generators, the deck can be adjusted. In this way, the deck is self-levelling. Thus in one example the generators may be actively controlled. One or more sensors attached to the deck and/or the hull sense motion of the respective part. Data captured by the sensors is passed to a processor. The processor, running suitable code that is stored in non-transient form in a memory, computes a required compliance of the generators for achieving a desired behaviour of the deck in response to forces on the hull. With suitable generators, that compliance may include positive drive by the generators in addition to energy capture. For example, if the sensors detect that the bow of the boat is experiencing an upward pitching force, generators in the front and rear of the boat may be made compliant and generators in the centre of the boat may be made stiff so that the hull can pitch under the deck with reduced motion of the deck.

Therefore, in some examples, the boat comprises an active control system. In some examples, the boat comprises a plurality of sensors (such as those shown at 108 and 208 in Figures 1 and 2 respectively). The sensors may be configured to sense loads on the hull or the deck. Each load sensor may be configured to sense the load at a respective position on the deck or hull. The positions of the load sensors may be fixed and/or known. Each linear generator may have a corresponding load sensor at its corresponding position. The control system may comprise a processor and a memory. The memory is arranged to communicate with the processor. The memory may be a non-volatile memory. The control system may comprise more than one processor and more than one memory. The memory may store data that is executable by the processor. By executing program code contained in such data, the one or more processors may perform functions as described herein. The memory may store such program code in a non-transitory manner. The processor may be configured to operate in accordance with a computer program stored in non-transitory form on a machine readable storage medium. The computer program may store instructions for causing the processor to perform its methods in the manner described herein.

The active control system may send instructions to the dampers to damp the motion of the deck in dependence on the data received from the load sensors. The active control system may vary the resistance to compression of individual energy capture mechanisms or individual dampers coupled to the energy capture mechanisms. Each linear generator may have a damper coupled to it in parallel, such that the resistance to compression of a damper influences how much the linear generator can compress.

By varying the resistance to compression of individual dampers coupled to the linear generators, the deck can be adjusted. The dampers may be adjusted in dependence on the load sensed by a load sensor corresponding to a respective damper. In this way, the deck damping of the deck can be actively controlled in response to loads sensed in different areas of the deck or the hull.

For example, the control system may instruct the energy capture mechanisms and/or dampers to damp the motion of the deck more in areas that are carrying a greater load to prevent damage to the payload and/or the deck. For instance, where a first load sensor located at a first position on the deck measures a greater load than a second load sensor located at a second position on the deck, the control system may increase the resistance to compression of a damper coupled to a linear generator at the first position.

The load sensors may be, for example, strain gauges. The processor of the active control system may process data from the load sensors and control the energy capture mechanisms in response to the sensed loads so as to at least partially stabilise motion of the deck about a horizontal axis. This may be used to vary the suspension of the deck with respect to position on the deck.

In other examples, the control system may control the energy capture mechanisms in response to data from other types of sensors. For example, LiDAR, radar, sonar or vision sensors may be used to acquire data indicative of the state of a body of water on which the boat is travelling (for example, sea state). The control system may control the plurality of energy capture mechanisms in dependence on data from such sensors. For example, the control system may control the energy capture mechanisms so as to increase their compliance when the sea is determined to be rough. This may improve the experience for passengers and/or protect cargo or other payloads carried by the boat. The boat may be provided with a drive mechanism for driving a load carried by the deck to move relative to the deck in the fore/aft direction of the boat. Using this drive mechanism the boat may be trimmed to cause it to adopt a preferred pitch state. In one convenient example the drive mechanism may be arranged to move an energy supply of the boat - for example a fuel tank or a battery - fore and aft. The energy supply may conveniently be mounted to the underside of the deck. In one example, the drive mechanism may be an electric motor coupled to a lead screw, with a power battery of the boat being coupled to the lead screw on a follower. The motor may be capable of moving the battery fore or aft by, for instance up to 1 m. In another example, the mechanism may comprise a linear ballscrew.

Therefore, the boat may comprise a mechanism for driving one or more payloads carried by the deck or within the hull to move relative to the deck or the hull, for example in the fore or aft direction of the boat (parallel to the longitudinal axis of the boat) and/or the port or starboard direction of the boat (perpendicular to the longitudinal axis of the boat). This can allow the position of a payload to be varied on the deck or within the hull. The mechanism may be configured to drive a payload in any desired position. For example, in the fore or aft directions, or the port and starboard directions. The one or more payloads may be any items carried by the boats as cargo or items used in the operation of the boat, such as a fuel tank or battery. As discussed above, there may be a plurality of load sensors attached to the deck and/or the hull. The sensors may sense motion of the deck and/or the hull. Data from the sensors is passed to a processor. The processor may be configured to process the data from the sensors (for example by running code stored in non-transient form in a memory) to determine the load at each load sensor and in response to the determined load(s), compute a compliance of each of the energy capture mechanisms for achieving a desired behaviour of the deck. Such embodiments do not require the presence of the energy capture mechanisms between the deck and the hull.

In some embodiments, in response to the sensed loads, a payload on the deck or within the hull may be moved relative to the deck and/or the hull. The payload may be moved to achieve a desired condition, such as an angle of trim of the boat in the water, or to distribute loads on the deck or in the hull to achieve better efficiency. Loads such as the traction battery may be moved in their relative positions to adjust the trim of the boat. This may improve efficiency and seakeeping. This approach could also be applied to the positions of, for example, ballast tanks, a pilot control console and seating, passenger seating and transported loads.

Once payloads on the deck or within the hull have been moved to the desired position using the mechanism for driving the payloads described above, the plurality of load sensors can be used to determine the load at different positions on the deck and the control system can control the energy capture mechanisms and/or the dampers in dependence on the measured loads to at least partially stabilise motion of the deck about a horizontal axis.

The boat may further comprise capacitors for energy storage. The capacitors may be electrically connected to the linear generators for charging and connected to an electric motor for discharge.

In another embodiment there is provided a boat having flexible edging surrounding at least a portion of a deck. The edging acts as a collar, attaching the deck to an internal side of the hull and forming a seal between the deck and hull. A plurality of linear generators coupled between the hull and the deck may be enclosed by the flexible edging. Movement of the hull relative to the deck transfers kinetic energy to the linear generators and the linear generators are configured to damp motion of the deck. The linear generators may be coupled to dampers. The dampers may be fluid bearings.

In another embodiment there is provided a rigid inflatable boat comprising at least one inflatable tube, a plurality of linear generators within the inflatable tube configured such that compression of the tube causes kinetic energy to be transferred to the linear generators. There may be two inflatable tubes opposed from each other, as shown in the cross-sectional view in figure 5. The internal pressure in the tube varies when forces are applied to the tube from the water.

In another embodiment there is provided a rigid inflatable boat comprising at least one inflatable tube, a hull, a deck, a plurality of energy capture mechanisms between the hull and deck, coupled such that movement of the hull relative to the deck transfers kinetic energy to the energy capture mechanisms. Within the inflatable tube, between the deck and hull, there is a deformable inner surface. The deformable inner surface serves as a seal to protect the energy capture mechanisms from water entering between the deck and hull.

The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In view of the foregoing description, it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.