Patent Description:
A well-known problem for boat owners is the growth of undesired organisms such as mussels, gastropods, algae, limpets and barnacles, which occurs on the underwater parts of a boat and leads, inter alia, to increased friction between the boat and the water, and hence to a lower speed and/or increased fuel consumption when the boat is driven. Such fouling may also make it harder to manoeuvre the boat.

The conventional way of preventing the growth of undesired organisms has been to paint the bottom of the boat with antifouling paint. This however has great environmental disadvantages as the antifouling paints used are often toxic to a varying degree.

As an alternative to painting with antifouling paint, recently various mechanical devices have been developed which are intended to counter and prevent fouling.

A type of hull protection device known as a hull protection cloth is sold under the trademark Clean Marine Tarp by Ekeröds Utvecklings AB in Löddeköpinge, Sweden. This hull protection cloth is a floating, special tarpaulin which is installed and secured to a mooring. When the boat is to be moored, it is driven onto the hull protection cloth. Direct contact between the hull protection cloth and the hull of the boat prevents the growth of undesired organisms.

Hull protection devices of this type are also known from the patent literature.

<CIT> describes a flexible mat which, after a boat hull has been driven onto it, presses up against the base of the hull to make a tight contact with this, whereupon the contact and movement between the mat and the boat hull prevents the growth of undesired organisms.

A disadvantage with known hull protection devices of this type is that they cannot be used for boats with a keel, since such boats cannot be driven onto the hull protection cloth or hull protection mat.

<CIT> discloses a hull protection device which comprises a casing which is intended to substantially enclose the underwater parts of the boat. For the boat to be able to drive into the hull protection device, weights are used for pulling down parts of the casing so that its sides hang substantially vertically in the water and allow passage for the boat in-between. When the boat has been driven into the hull protection device, measures must be taken to evacuate the water from the hull protection device and to allow the casing to lie closely against the underwater parts of the boat.

<CIT> describes a hull protection device which comprises a casing intended to form a pocket with stationary water around the boat which is impermeable to light. In this case too, weights are used to weigh down parts of the casing to make it possible for the boat to be driven into the hull protection device. When the boat is in place in the hull protection device, the pocket with stationary water is created, for example in that the weights are lifted up or the open part of the casing is closed.

A disadvantage of this type of hull protection device is that measures are required to bring the casing into an active position when the boat has been driven into the hull protection device. This means that the device is complicated to use and costly to produce.

An object of the invention is to at least partly overcome one or more of the limitations of the known techniques.

Another object is to provide a hull protection device which can be used for a boat with keel.

A further object is to provide a hull protection device which protects as large portion of the underwater parts of a boat as possible.

Yet another object is to provide a hull protection device which is simple to use.

One or more of these objects, and further objects which may arise from the description, is/are achieved at least partially with a hull protection device according to the independent claim. Embodiments of the invention are defined by the dependent claims.

According to a first aspect of the invention, there is provided a hull protection device which is designed to counter the growth of undesired organisms on underwater parts of a boat and which comprises a floating hull protection cloth onto which the boat is intended to be driven to counter the growth of the undesired organisms on the underwater parts by contact and movement/friction between the hull protection cloth and the underwater parts. The hull protection cloth is designed to float horizontally in the water when the hull protection device is not used by the boat. The hull protection cloth has a slot which allows use of the hull protection device when the boat is provided with a keel, in that the keel is driven into the slot when the boat is driven onto the hull protection cloth. The hull protection device is provided with a stabilising device which prevents the slot from opening when the boat is being driven onto the horizontally floating hull protection cloth or is situated thereon.

By providing the hull protection device with a slot, it can be used for boats with keel, and by means of the stabilising device, the width of the slot can be stabilised such that the hull protection cloth protects the parts of the hull which lie level with the keel and behind it.

Further objects, characteristics, aspects and advantages of the present invention will arise from the following detailed description, the attached claims and the drawings.

Embodiments of the invention will now be described in more detail with reference to the appended schematic drawings.

In the description below, the terms "back" and "front" are used in relation to various parts of a hull protection device. The terms are used throughout such that "front" refers to a part which lies closer to the quay when the hull protection device is placed at a mooring, and closer to the bow of the boat when the boat is placed on the hull protection device, while "back" refers to a part which lies further away from the quay when the hull protection device is placed at a mooring, and closer to the stern of a boat when the boat is placed on the hull protection device. This applies when the hull protection device is placed with its short side against the quay so that the boat is intended to be placed on the hull protection device with the bow pointing towards the quay. At other positions, e.g. if the hull protection device is placed with a long side against the quay so the boat is intended to be placed on the hull protection device parallel to the quay, "front" refers to a part which lies closer to the intended placing of the bow on the hull protection device, while "back" concerns a part which lies closer to the intended placing of the stern on the hull protection device.

<FIG> shows schematically a hull protection device <NUM> which is designed to counter the growth of undesired organisms on underwater parts of a boat. The hull protection device <NUM> comprises a hull protection cloth <NUM> onto which the boat is intended to be driven when the hull protection device <NUM> is used in the water. When the hull protection device is not used by a boat, the hull protection cloth <NUM> is designed to float horizontally in the water and thus extend in the plane of the water surface. The hull protection cloth <NUM> is provided with a slot <NUM> which thus forms a cutout in the hull protection cloth <NUM> and, as in this example, extends in the longitudinal direction of the hull protection cloth from the middle of a short side <NUM> of the hull protection cloth. The slot <NUM> allows use of the hull protection device <NUM> when the boat is provided with a keel, in that the keel is driven into the slot <NUM> when the boat is driven onto the hull protection cloth <NUM>.

As <FIG> shows, the hull protection device <NUM> may also be provided with a keel protection device <NUM> to protect the keel from growth of undesired organisms. The keel protection device <NUM> comprises two keel protection curtains <NUM> which are designed, on use of the keel protection device <NUM> in the water, to hang down from their respective long sides <NUM> on the slot <NUM> and in this way fully or partially protect the keel, in a similar manner to the protection of the underwater parts of the boat hull by the hull protection cloth <NUM>, i.e. primarily through contact and movement/friction between the boat and the hull protection device <NUM>.

According to the invention, the hull protection device <NUM> is furthermore provided with a stabilising device (not shown in <FIG>), which prevents the slot <NUM> from opening when the boat is driven onto the hull protection device, and which thus ensures the function of the hull protection device. The stabilising device will be described in more detail below with reference to <FIG>.

<FIG> shows schematically how a hull protection device <NUM> may be used for a boat <NUM> with a keel <NUM>. The boat, which in this example is a sailing boat, is driven with its hull <NUM> onto the hull protection device <NUM>, and the keel <NUM> is driven into the keel protection device <NUM> via the slot <NUM>.

The sailing boat <NUM> shown in <FIG> has a fin keel. The hull protection device <NUM> may however also be used by boats with other types of keel, for example a centreboard, bilge keel, bulb keel, swing keel and canting keel. The person skilled in the art will understand that certain dimensions and details of the hull protection device may need to be adapted to specific keel designs.

It is stated above that the boat <NUM> is driven onto the hull protection cloth <NUM>. In some cases, it may be placed on or moved onto this in other ways. It may for example be sailed onto the hull protection cloth, dragged onto this or otherwise moved relative to this so that it is positioned on the hull protection cloth <NUM>. For the sake of simplicity however, it is stated only that the boat is driven onto the hull protection cloth, but this expression is intended also to include other ways of placing the boat <NUM> on the hull protection cloth <NUM>. Furthermore, the expressions "the boat <NUM> is driven onto the hull protection cloth <NUM>" and "the boat is driven onto the hull protection device <NUM>" are indistinguishable.

The actual hull protection cloth <NUM> may be formed in a similar fashion to the known hull protection cloths for a boat without keel. It may have a lower density than water so that it floats on water. To this end, for example it may be formed by a layer of foam with air-filled cells which are fully or partly covered on both sides by a protective tarpaulin made of a woven plastic material, which may consist of polyolefin plastic or another plastic material such as PVC. The thickness of the hull protection cloth <NUM> may for example be around <NUM> - <NUM> for a sailing boat of the leisure type. For other boats, the thickness may be different. The shape of the hull protection cloth may vary depending on the design of the mooring where it will be used, and the type of boat for which it is intended. Normally however it is largely rectangular, but for example the short sides <NUM> may have a different shape, as will be explained below. The hull protection cloth may be provided with conventional devices (not shown) for anchoring it to the mooring at one or more places.

In contrast to a conventional hull protection cloth for boats without keel, the hull protection cloth <NUM> for boats with keel is thus provided with a slot <NUM> which allows boats with keel to drive onto the hull protection cloth <NUM>. The width and length of the slot <NUM> may be adapted to the type of boat and keel for which the hull protection device <NUM> is intended. A width of the slot <NUM> for a sailing boat of the leisure type may typically be <NUM> to <NUM>, preferably <NUM> to <NUM>. It is desirable that the slot is as narrow as possible, but still leaves room for the keel. The length of the slot <NUM> is adapted to where the keel begins on the type of boat for which the hull protection device <NUM> is intended.

The keel protection device <NUM> may in some embodiments have a density which is slightly lower than that of water so that it just floats, but has no lifting force. When the hull protection device <NUM> is lying in the water without being used by a boat, the keel protection device <NUM>, as shown in <FIG> and <FIG>, is designed to hang down from the hull protection cloth <NUM>, preferably vertically in the water, i.e. perpendicularly to the water surface. To this end, it may be provided with weights on its lower edge. The keel protection device <NUM> may be made from a woven plastic material, which may consist of polyolefin plastic or another plastic material such as PVC. It may be fastened to the hull protection cloth along the edges of the slot <NUM>, or be formed integrally with the protective tarpaulin of the hull protection cloth <NUM>. The keel protection device <NUM> may preferably have an uninterrupted surface on the respective side of the slot <NUM>.

As the person skilled in the art will understand, the depth of the keel protection device <NUM> may be adapted to the type of keel concerned. In certain embodiments, the keel protection device <NUM> may extend down to or past the lower edge of the keel. In other embodiments, the lower edge of the keel protection device may be designed to lie at a shallower depth than the lower edge of the keel. This may for example be suitable when the keel is a bulb keel. Then the lower edges of the keel protection curtains <NUM> end above the bulb.

The weight or weight loading of the keel protection device <NUM> may be adapted such that the respective keel <NUM> runs smoothly in and out of the keel protection device <NUM>, and so that contact between the keel protection device <NUM> and the keel <NUM> is maximised. Furthermore, the flexibility of the keel protection device may be adapted such that the keel protection device has sufficient contact with and movement against the keel to prevent the growth of undesired organisms, and so that the keel runs smoothly in and out of the keel protection device.

Depending on the type of keel <NUM> for which the hull protection device <NUM> is intended, the keel protection device <NUM> may be fully closed, partly closed/open, or fully open at the bottom.

In certain embodiments, the keel protection curtains <NUM> may be connected together along their lower edges directly or indirectly via a bottom part. In this way, a pocket with for example a V-shaped or U-shaped cross-section can be formed for the keel <NUM>. The person skilled in the art will understand that the shape of the keel protection curtains <NUM> and the cross-section of the keel protection device <NUM> may be varied in other ways for adaptation to different keel types. As an alternative, the keel protection device <NUM> may for example be formed in one piece as a pocket which is closed at the bottom, so that the keel protection device <NUM> surrounds the keel on the sides and bottom. In this case, the side parts of the pocket also form part of the keel protection curtains <NUM>. A fully or partly closed lower edge of the keel protection device <NUM> may contribute to holding the keel protection curtains <NUM> close to the keel.

Depending on various requirements for moorings for which the hull protection device is intended, the keel protection device <NUM> may be fully closed, partly closed/open, or fully open at its front edge, i.e. in the direction against the bow of the boat when the boat is placed on the hull protection device.

In certain embodiments, the keel protection curtains <NUM> may furthermore be directly or indirectly connected together at the front edges. Alternatively, the keel protection device may be formed in one piece as a pocket which is closed at the front, and the side parts of which form the keel protection curtains <NUM>. In this case therefore, the keel protection device <NUM> surrounds the keel at the front and the sides. As stated above, the pocket may also be closed at the bottom so that the keel is also enclosed underneath.

In further embodiments, the keel protection device <NUM> may be formed such that the keel partly extends past the front edge of the keel protection device <NUM>.

The keel protection device <NUM> may in certain embodiments be provided with rods which run in horizontal channels on the outsides of the keel protection curtains <NUM>. These rods may contribute to creating a desired cross-section of the keel protection device for adaptation to different keel types. Finally, it should be pointed out that the keel protection device may be used together with a hull protection cloth without stabilising device or together with any stabilising device.

<FIG> and <FIG> show schematically an example of a hull protection device <NUM> in more detail. In this example, the hull protection cloth <NUM> is largely rectangular, but the corners of the front short side <NUM> are cut off to avoid forming a surface for birds to settle on, and to reduce the weight of the hull protection cloth. The rear short side <NUM> is furthermore configured so as to make it easier for the keel <NUM> of the boat <NUM> to drive into the slot <NUM>.

As shown in <FIG>, the rear opening of the keel protection device <NUM>, or more specifically the rear edges <NUM> of the keel protection curtains <NUM>, extend perpendicularly to the hull protection cloth <NUM> when the hull protection device <NUM> lies in the water without any boat <NUM>. The rear edges in this case form an angle β which is <NUM>° to the long sides <NUM> of the slot <NUM>, or the plane of the hull protection cloth <NUM>. To make it easier for the keel to run into the keel protection device <NUM>, the rear edges <NUM> of the keel protection curtains <NUM> may be arranged to form an angle β in the range from <NUM> to <NUM>° with the long sides <NUM> of the slot <NUM>, or the plane of the hull protection cloth <NUM> when the hull protection device <NUM> is lying in the water without a boat <NUM>. Usually, the angle β should not be smaller than necessary for the keel protection device to cover the entire keel, so as to prevent the growth of undesired organisms over the entire keel.

To further facilitate the driving of the boat <NUM> onto the hull protection device <NUM>, the rear short side <NUM> of the hull protection cloth <NUM> may be configured so as to form a guide for the boat in the direction towards the slot <NUM>, and so that the mouth of the slot <NUM> is visible to the boat's operator. This may be achieved by the hull protection cloth <NUM> being configured such that an angle γ formed between its long sides <NUM> and its rear edges <NUM> is less than <NUM>°.

When the hull protection cloth <NUM> is provided with a slot <NUM>, several different problems may occur. One problem is that the slot risks opening at the rear part when the boat is driven onto the hull protection device <NUM> and is situated thereon. More specifically, the slot <NUM> can open as an inverted V-shape, viewed in the direction towards the front part of the hull protection cloth <NUM>, which means that the underwater parts of the hull which lie level with and behind the keel are not covered by the hull protection cloth <NUM>. If the hull protection device is provided with a keel protection device, the problem may also arise that the keel protection device does not lie sufficiently close to the keel and therefore does not protect this optimally. In addition, the hull protection cloth <NUM> risks creasing along the length of the slot <NUM> and floating up against the sides of the boat when the boat is driven onto the hull protection device <NUM>. This can also contribute to the hull protection device <NUM> not protecting the boat optimally. A further problem may be that the slot also risks opening at its front part, which can lead to the hull protection cloth <NUM> breaking in that region. It is thus desirable that the hull protection device <NUM> is formed so that the slot <NUM> is held together along its entire length.

To solve the above-mentioned problems fully or partly, the hull protection device <NUM> according to the invention is provided with a stabilising device <NUM> which prevents the slot <NUM> from opening when a boat is driven onto or is situated on the hull protection device.

The stabilising device <NUM>, which is shown in <FIG> and <FIG>, may be mounted on the underside of the hull protection cloth <NUM>, and may more particularly comprise two slot rods <NUM> which extend longitudinally along the long sides <NUM> of the slot <NUM> in order to stabilise this. It may furthermore comprise a first stabilising mechanism which is designed to prevent the slot from opening in its front part, and/or a second stabilising mechanism which is designed to prevent the slot from opening in its rear part, when the boat <NUM> is driven onto or situated on the hull protection device. The stabilising device is thus designed to stabilise the width of the slot <NUM> so that the width remains substantially constant.

The two slot rods <NUM> preferably have a higher bending resistance in the slot transverse direction, i.e. horizontally, than in the slot longitudinal direction, i.e. vertically. This ensures a restriction of the movement of the hull protection cloth <NUM> perpendicularly to the length direction of the slot <NUM>, while retaining the flexibility and bendability of the hull protection cloth <NUM> in its longitudinal direction so that it can follow the hull of the boat. To this end, the slot rods <NUM> may for example have a rectangular cross-section and their width may be substantially greater than their height. The slot rods <NUM> may extend from the rear end of the slot <NUM> to past the front edge of the slot. In certain embodiments, the slot rods <NUM> may be arranged in channels <NUM>, preferably with a close fit, so as to counter the creasing of the hull protection cloth <NUM>. The slot rods <NUM> may for example consist of a composite material in which the contained fibres may be made of glass or a polymer material.

The first stabilising mechanism may comprise a first spacer element <NUM> which extends transversely between the slot rods <NUM> in front of the front end of the slot, preferably close to the front end of the slot, and which are designed to prevent the slot rods <NUM> from moving apart at the front end of the slot <NUM> when a boat is driven onto the hull protection cloth <NUM> or is situated thereon. The first spacer element <NUM> may be flexible so as to follow the hull of the boat and allow the boat to move onto the hull protection cloth <NUM>. It is designed to absorb traction forces which act on the slot rods <NUM> when the boat is driven onto the hull protection device <NUM> or is situated thereon. To this end, the first spacer element <NUM> may be made of a material with a high modulus of elasticity and very high tensile strength. It may for example be made of a strong woven plastic material which may consist of olefin plastic or another type of plastic material such as PVC. In certain embodiments, it is made in one piece with the hull protection cloth <NUM>. The first spacer element <NUM> is attached to the slot rods <NUM>.

<FIG> shows an example of a possible design of the first spacer element <NUM>. In this case, the spacer element at each end has an attachment <NUM> in the form of a loop. The first spacer element <NUM> may be fastened transversely between the slot rods <NUM> in that the slot rods <NUM> are threaded through the loops <NUM>. If the slot rods are placed in channels <NUM>, openings may need to be made therein at the point where the first spacer element <NUM> is to be fastened.

The stabilising device <NUM> may as stated also comprise a second stabilising mechanism which prevents the slot <NUM> from opening at its rear part. In the embodiment of the stabilising device <NUM> shown in <FIG> and <FIG>, the second stabilising mechanism comprises a second spacer element <NUM> which extends transversely between the slot rods <NUM> in front of the first spacer element <NUM>, and is designed to prevent the slot rods <NUM> from moving towards one another at the front parts when the boat <NUM> is driven onto the hull protection device or is situated thereon. The second spacer element <NUM> is thus designed to absorb compression forces which act on the slot rods <NUM> in the front part thereof when the boat is driven onto or is situated on the hull protection cloth <NUM>. To this end, the second spacer element <NUM> may consist of metal or other material with a high bending strength. It may thus be rigid. To allow the boat <NUM> to drive onto the hull protection cloth <NUM>, the second spacer element <NUM> may have a form which is adapted to a boat hull. The distance between the first spacer element <NUM> and the second spacer element <NUM> may vary depending on the size and type of boat for which the hull protection device <NUM> is intended.

In a variant of the embodiment of the stabilising device <NUM> shown in <FIG> and <FIG>, the distance between the first spacer element <NUM> and the second spacer element <NUM> may be made larger so that the second spacer element <NUM> is placed in a position where the hull of a boat which is driven onto the hull protection device <NUM> begins to bend upward towards the bow. In such a case, the shape of the second spacer element <NUM> need not be adapted to the boat hull, but the second spacer element <NUM> may instead be straight. A straight spacer element may be easier to produce and allow a wider choice of materials. With a greater distance between the first and second spacer elements <NUM>, <NUM>, the stress on the second spacer element <NUM> is also reduced, which in turn may also have an advantageous effect on the production and choice of material. Furthermore, the channels <NUM> may terminate directly after the first spacer element <NUM> in the direction towards the front end of the hull protection device, and the slot rods <NUM> may extend out of and past the channels <NUM> in the direction towards the front end of the hull protection device so that they run clear of the channels for a short distance in front of the first spacer element <NUM>. Therefore the hull cloth <NUM> may be fully smooth above the second spacer element <NUM>. Since the second spacer element <NUM> prevents the slot rods <NUM> from being pressed towards one another at their front ends, the slot <NUM> cannot widen at its rear part when a boat is driven onto the hull protection cloth <NUM> or is situated thereon.

In the embodiment shown in <FIG>, the hull protection device is furthermore provided with one or more pairs of transverse rods <NUM> which extend in channels <NUM> from a respective side edge <NUM> of the hull protection cloth <NUM>, transversely across the hull protection cloth <NUM>, to the respective long side <NUM> of the slot <NUM>. The transverse rods <NUM> and channels <NUM> may more particularly preferably extend to the respective edge of the slot rods <NUM>. The design of the transverse rods <NUM> and channels <NUM> is preferably selected so that they together prevent the hull protection cloth <NUM> from creasing when a boat is driven onto or is situated on the hull protection cloth <NUM>.

The transverse rods <NUM> may have a rectangular cross-section. In certain embodiments, they may be made of a composite material in which the contained fibres may be made of glass, or a polymer material, and it is desirable that they have a bending strength which makes them sufficiently rigid to prevent creasing but sufficiently flexible to follow the curved surface of the hull up to the waterline. The bending resistance for the transverse rods <NUM> may need to be varied depending on the design of the hull of the sailing boat, and the angle α of the channels <NUM> (see <FIG>) against the long sides <NUM> of the slot <NUM> may vary depending on the design of the boat hull.

<FIG> shows an example of a possible design of the second spacer element <NUM>. In the same way as the first spacer element <NUM>, the second spacer element <NUM> has an attachment <NUM> at each end which takes the form of a loop. The second spacer element <NUM> may be fastened transversely between the slot rods <NUM> in that the slot rods <NUM> are drawn through the loops.

<FIG> shows schematically a second embodiment of the stabilising device <NUM> which is suitable for moorings with Y-shaped beams <NUM> and associated floats <NUM> at the rear ends of the Y-shaped beams, or for other moorings which have a form of equivalent support at the rear part of the mooring, e.g. posts which are anchored at the bottom and extend up over the water surface. In this embodiment, in the same way as in <FIG> and <FIG>, the stabilising device <NUM> comprises slot rods <NUM> which extend along the long sides <NUM> of the slot <NUM>, and a first stabilising mechanism in the form of a first spacer element <NUM> which extends transversely between the slot rods <NUM> in front of the front end of the slot, and which is designed to prevent the slot rods <NUM> from moving apart at the front ends of the slot <NUM> when a boat is driven onto the hull protection cloth <NUM> or is situated thereon. The second stabilising mechanism comprises two side edge rods <NUM> which extend along the side edges <NUM> of the hull protection cloth <NUM>, and a third spacer element <NUM> which extends transversely between the side edge rods <NUM> and which is designed to limit the distance between the side edge rods <NUM>, i.e. hold these together, at the front end of the slot when the boat is driven onto the hull protection cloth <NUM> or is situated thereon. The second stabilising mechanism may also comprise at least one pair of transverse rods <NUM> of similar type to those shown and described in connection with <FIG>.

The side edge rods <NUM>, as shown in <FIG>, may extend from the rear end of the hull protection cloth <NUM> to at least past the front ends of the slot rods <NUM>. They may be anchored at one or more points against the side edges <NUM> of the hull protection cloth <NUM>. The rear ends of the side edge rods <NUM> are designed to lie close to or against the inside of the respective float <NUM> when the hull protection device <NUM> is mounted at the mooring, as shown in <FIG>. In other embodiments, the rear ends of the side edge rods <NUM> may lie against posts which form part of the mooring. The length of the side edge rods <NUM> may in certain cases have to be adapted to the length of the mooring, so that they extend past the rear short side <NUM> of the hull protection cloth <NUM>. In certain cases, the mooring may also be adapted in various ways to the size of the hull protection device so that it functions optimally.

The side edge rods <NUM> may have a high bending resistance in both directions, i.e. both vertically and horizontally. They may for example have a rectangular or circular cross-section. In certain embodiments, they may be made of composite material in which the contained fibres may be made of glass or a polymer material. Alternatively, they may be made of a pure polymer material or wood.

The third spacer element <NUM> may consist of a material which has a high modulus of elasticity and very high tensile strength. It may for example be made of a strong woven plastic material, which may consist of olefin plastic or another type of plastic material such as PVC. In certain embodiments, the third spacer element <NUM> is fastened to the side edge rods <NUM> in front of the front edge of the slot <NUM>. The first spacer element <NUM> may then be fixedly connected to the third spacer element <NUM>. It may e.g. be welded to this. In other embodiments, the first spacer element <NUM> and the third spacer element <NUM> may be placed at different distances from the front edge of the slot <NUM>, i.e. at different locations.

The transverse rods <NUM>, which may be arranged in channels <NUM> in the same way as in <FIG>, in this embodiment are fastened to the side edge rods <NUM>. A first pair of transverse rods <NUM> is placed at the rear ends of the hull protection cloth <NUM>. One or more further pairs of transverse rods <NUM> may be placed between the rearmost pair and the third spacer element <NUM>. At least the rear pair of transverse rods <NUM> may be dimensioned and arranged so as to prevent the rear part <NUM> of the slot from opening. Other pairs may contribute to maintaining a constant width of the slot. All transverse rods <NUM> may also be arranged so as to prevent creasing of the hull cloth <NUM>.

In the embodiment of the stabilising device <NUM> shown in <FIG>, the side edge rods <NUM> via their contact against the floats <NUM>, together with the transverse rods <NUM>, prevent the slot <NUM> from opening at its rear part when a boat is driven onto the hull protection cloth <NUM> or is situated thereon. At the same time, the third spacer element <NUM> prevents the front parts of the side edge rods <NUM> from being moved apart, and thus ensures that the side edge rods <NUM> remain lying against the floats <NUM>.

<FIG> shows a possible design of the third spacer element <NUM> with the first spacer element <NUM> fastened thereto. The third spacer element <NUM> has at each end an attachment <NUM> in the form of a loop through which the respective side edge rod <NUM> may be threaded.

In a third embodiment of the stabilising device <NUM>, the second stabilising mechanism may comprise a fourth spacer element in the form of a profile <NUM> which is designed to be anchored in the rear part of the hull protection cloth <NUM> or at the rear edge of the keel protection device <NUM>. The profile <NUM> may have a form which follows the cross-section of a keel of the boat for which the hull protection device <NUM> is intended, and thus has a shape which corresponds to a desired cross-section of the keel protection device <NUM>. The profile <NUM> serves to stabilise the slot <NUM> and prevent this from opening when a boat is driven onto or is situated on the hull protection device. It may also contribute to allowing the keel to run in and out of the keel protection device. In certain embodiments, the profile <NUM> may consist of a composite material in the form of a rectangular or round rod, in which the contained fibres may be made of glass or a polymer material. Alternatively, it may consist of a pure polymer material.

<FIG> shows schematically two possible embodiments of the profile <NUM>. The profile <NUM> shown in <FIG> has substantially a U-shape with two side arms <NUM> which are designed to extend in the transverse direction relative to the longitudinal direction of the slot <NUM>. The profile <NUM> shown in <FIG> is formed accordingly but is rounded at its lower part in order to be used for example for a bulb keel.

<FIG> shows schematically a fourth embodiment of the stabilising device <NUM> which is a variant of the embodiment shown in <FIG>. In this embodiment, in the same way as the embodiment shown in <FIG> and <FIG>, the stabilising device <NUM> comprises slot rods <NUM> which extend along the long sides <NUM> of the slot <NUM>, and a first stabilising mechanism in the form of a first spacer element <NUM> which extends transversely between the slot rods <NUM> in front of the front end of the slot, and is designed to prevent the slot rods <NUM> from moving apart at the front end of the slot <NUM> when a boat is driven onto the hull protection cloth <NUM> or is situated thereon. The second stabilising mechanism, in the same way as in <FIG>, comprises side edge rods <NUM> which in this embodiment form part of a frame <NUM> which extends along the side edges of the hull protection cloth <NUM> and at the edge of its front part. If the hull protection cloth <NUM> is rectangular, the frame may thus consist of two side edge rods <NUM> which extend along the side edges <NUM> of the hull protection cloth <NUM>, and a front edge rod <NUM> which extends along the front short side <NUM> of the hull protection cloth <NUM>. If the hull protection cloth <NUM> has a different form in its front part, the frame <NUM> may comprise, in addition to two side rods <NUM> and a front edge rod <NUM>, further rods which follow the edges of the hull protection cloth in the front part of the hull protection cloth. <FIG> shows an example where the frame <NUM> comprises two slanting edge rods <NUM> which frame the front pointed part of the hull protection cloth <NUM>. The various rods used in the frame <NUM> may be formed in a similar fashion to that described for the side edge rods <NUM> in connection with <FIG>. The frame <NUM> may preferably be floating. In a similar manner to the embodiments of the second stabilising mechanism shown in <FIG>, this embodiment may comprise a third spacer element <NUM> which extends between the side edge rods <NUM> and is designed to limit the distance between the side edge rods <NUM> at the front end of the slot <NUM>, and at least one pair of transverse rods <NUM> which are fastened to the side edge rods <NUM> and placed at the rear ends of the hull protection cloth <NUM> in order to prevent the slot <NUM> from opening at its rear end.

The embodiment shown in <FIG> may be suitable for use when the hull protection device <NUM> is to be used at a quay where there are neither posts, Y-beams nor other similar devices. As the frame <NUM> is rigid and the hull protection cloth <NUM> is anchored therein, the side edge rods <NUM> together with the transverse rods <NUM> prevent the slot <NUM> from opening at its rear part when a boat is driven onto or is situated on the hull protection cloth <NUM>. The third spacer element <NUM> can absorb forces which act to move the side edge rods <NUM> apart, but may also be used so as to smoothly fasten the hull protection cloth <NUM> to the frame <NUM>. The hull protection cloth <NUM> may however be fastened to the frame <NUM> in another way and the third spacer element <NUM> omitted.

<FIG> shows schematically a further variant of the hull protection device <NUM>. The stabilising device <NUM> in this case comprises a frame <NUM> which is of the same type as that shown in <FIG>, and in which the hull protection cloth <NUM> is fastened, and one or more pairs of transverse rods <NUM>, which are of the same type and arranged in the same way as previously described in connection with the embodiment shown in <FIG> and <FIG>. A first pair of transverse rods <NUM> may be placed at the front part of the slot <NUM> and is designed to prevent the slot <NUM> from opening at its front part. They thus constitute a first stabilising mechanism. A second pair of transverse rods <NUM> is placed at the rear end of the hull protection cloth <NUM> and is designed to prevent the slot <NUM> from opening at its rear part. They thus constitute a second stabilising mechanism. One or more further pairs of transverse rods <NUM> may be placed between the rear pair and the front pair so as to further stabilise the width of the slot.

In the embodiment shown in <FIG>, thus the stabilising device <NUM> comprises no transverse rods <NUM> or spacer elements <NUM>, <NUM>, <NUM> of the type found in the embodiments in <FIG>, <FIG> and <FIG>. This means an increased load on the transverse rods <NUM>, which may mean that the material and dimensions thereof must be adapted. The embodiment in <FIG> may naturally be supplemented with slot rods <NUM>.

Claim 1:
Hull protection device (<NUM>) which is designed to counter the growth of undesired organisms on underwater parts of a boat (<NUM>) and which comprises a floating hull protection cloth (<NUM>) onto which the boat is intended to be driven to counter the growth of the undesired organisms on the underwater parts by contact and movement/friction between the hull protection cloth (<NUM>) and the underwater parts, characterized in that
the hull protection cloth (<NUM>) is designed to float horizontally in the water when the hull protection device is not used by the boat;
the hull protection cloth (<NUM>) has a slot (<NUM>) which allows use of the hull protection device (<NUM>) when the boat (<NUM>) is provided with a keel (<NUM>), in that the keel is driven into the slot (<NUM>) when the boat is driven onto the hull protection cloth; and
the hull protection device is provided with a stabilising device (<NUM>) which prevents the slot (<NUM>) from opening when the boat is being driven onto the horizontally floating hull protection cloth (<NUM>) or is situated thereon.