WO2009127804A2

WO2009127804A2 - Sailing vessel

Info

Publication number: WO2009127804A2
Application number: PCT/GB2009/000779
Authority: WO
Inventors: Michael De Lacy Barton
Original assignee: Michael De Lacy Barton
Priority date: 2008-04-16
Filing date: 2009-03-25
Publication date: 2009-10-22
Also published as: WO2009127804A3; GB0806892D0

Abstract

A sailing vessel comprises a mast (1) that is movably mounted in a manner that allows it to be moved towards the port side or the starboard side of the vessel. Two supports (2,3) can be operably attached at either side of the mast (1), with the bases of the supports (2,3) being mounted in a manner that allows them to be moved in a different direction from the direction in which the mast (1) can be slid. Preferably the mast (1) and supports (2,3) are slidably mounted. The invention facilitates rapid adjustment of the positioning of a sail in a manner that can be used to catch the wind efficiently. It can also be used to generate lift and reduce drag.

Description

Sailing vessel

The present invention relates to an improved sailing vessel and to novel components thereof.

The basic design of many sailing vessels has not changed for hundreds of years. There is normally at least one mast in a fixed position, one or more sails that are supported by the mast and a system of rigging for adjusting the sails to take into account the wind direction and wind speed.

The mast is generally located along a central axis running from bow to stern. Typically it is located towards the bow of the vessel and has a swinging boom attached to it. The sail is controlled by a rigging that system, which can be complex and requires experience to operate safely.

The present invention takes a radically different approach to existing sailing vessels.

According to the present invention there is provided a sailing vessel comprising a mast that is mounted in a manner that allows it to be moved during sailing from a central position towards the port side or the starboard side of the vessel.

Preferably the mast is supported by at least one movably mounted support.

More preferably, there are two movably mounted supports that engage the mast, with the base of one support being located towards the port side of the mast and the base of the other support being located towards the starboard side of the mast.

The supports and/or mast are desirably slidably mounted at their bases. This can be achieved by using sliders that slide upon one or more tracks that are secured to the vessel. The tracks can be straight or curved

Thus each slider may have its own track. Alternatively, there may be a single track, which is preferably curved, with the sliders positioned at different locations along it.

The invention allows a sail to be positioned for catching the wind in a highly efficient manner. It is particularly suitable for allowing the centre of the sail to be positioned over the centre of gravity of the vessel.

The present invention also allows the sail to be adjusted when the wind direction changes. This can be done easily and rapidly, without the need for complex rigging.

The sail can be positioned in a manner that allows a degree of lift. This allows the drag on the vessel to be reduced, because the vessel lifts to some degree out of the water and there is therefore less surface area in contact with the water. This results in an increase in the speed that can be achieved.

The vessel may optionally be fitted with hydrofoils. This is particularly preferred if the vessel is a multihull vessel (e.g. a catamaran, a trimaran or higher). At high wind speeds lift generated by the sail may be such so that only the hydrofoils are in the water. The water resistance is then very low allowing even higher speeds to be achieved. Indeed it is envisaged that a vessel of the present invention might even be used to break existing sailing records.

The invention can also be used to reduce fuel consumption. It can be used to modify a powered vessel so as to harness wind energy and thereby to reduce the power output required (e.g. to reduce the power supplied to a propeller).

For example, a movable mast that that is controlled via one or more movable supports of the present invention may be added to a large ship such as an oil tanker, a container ship or a cruise ship so that it can be used to support a sail and harness the wind to reduce the fuel consumption. A plurality of movable masts and associated supports may even be fitted so that several mainsails can be used.

In some cases the invention may be used to provide additional power. It is known to tow generators behind sailing vessels so as to charge batteries, for example. Given that the present invention allows high speeds to be achieved by efficiently harnessing wind power, it can therefore be used to provide significant amounts of charge to generators.

The invention has been briefly described in the foregoing paragraphs, but is set out in further detail in the accompanying claims. The main claims set out the invention in broad form and the dependent claims set out various preferred aspects of the invention.

It can be seen from the claims that, in addition to sailing vessels per se, the invention also covers methods of sailing, kits, and methods of modifying vessels.

Non-limiting illustrative examples of the present invention will now be provided, with reference to the accompanying drawings; wherein:

Figures 1 to 3 show a prototype catamaran of the present invention with the main sail at a central position. The sail shown in Figures 1 to 3 (as well as in subsequent Figures 4 to 8) is a small one that is shown only for illustration and therefore is not fitted tightly to the boom or mast. In practice a larger sail would of course normally be used, which would be shaped to fit closely between the boom and mast, as is well known in the art of sailing.

Figures 4 to 7 show the catamaran with the sail positioned towards the starboard side of the boat

Figures 8 and 9 show the catamaran with the sail positioned towards the port side of the boat.

Figure 10 shows a view of the top of a support that is located on the port side of the catamaran and engages a track located on the near side of the mast (as shown in the figure) via a slider. Another track is shown on the far side of the mast and is engaged by a slider connected to a further support on the starboard side of the catamaran.

Figure 11 shows a resilient spring located at the base of a support, together with a slider located beneath the spring and ropes that can be used to move the support forwards or backwards (via a rope and pulley system). A similar arrangement is provided at the base of the other support and of the mast.

Figure 12 shows the position at which a rudder would be located on the port hull of the catamaran. (A similar rudder would of course also be located at the corresponding position for the starboard hull.)

Figure 13 shows a set of jam cleats that can be used to releasably secure a rope in a given position. Jam cleats can be used to secure the mast and supports in desired positions for given wind conditions/a given manoeuvre of the boat, until it is desired to change these positions (e.g. in response to a change in the wind).

Figures 14 and 15 show a larger sail on the catamaran than the sail shown in Figures 1 to 8. The larger sail is closer in size to the size to a sail that that would normally be used in practice, although the shape would differ so as to better fit between the boom and mast. (The sail shown is a spare one that was available at the time for demonstration purposes, but is not specifically shaped for the boat.)

Figure 16 is a schematic plan view illustrating how control ropes can be used to move a mast and associated supports of the present invention. For simplicity the tracks, along which the mast and supports would be moved, are not shown in this figure. (Examples of such tracks and a framework for such tracks are shown in Figures 17 to 20 instead.) The sail, boom and sailing vessel are also not shown.

Figures 17 to 20 show examples of tracks along which a mast and associated supports can be moved. A framework for supporting such tracks is also shown. . For simplicity, the control rope system, winch, etc., used to move such the mast and supports is not shown, these components already being illustrated by Figure 16. The sail, boom and sailing vessel are also not shown.

Figure 21 illustrates an embodiment of the invention in which hydraulic rams are used. Hydraulic rams can be used to increase or decrease the length of supports for the mast and can thereby be used to further adjust the orientation of the mast.

Example 1 Example of a catamaran of the present invention

A prototype of a catamaran of the present invention is illustrated by the prints shown in Figures 1 to 15. The catamaran is shown ready for sailing, once rudders and a closer fitting sail has been attached. (As indicated earlier the sails shown in the figures are for illustration only).

In a preferred embodiment the catamaran would also include hydrofoils, as discussed later. However they are not essential and are therefore not shown in the figures.

As can be seen from the figures, the catamaran shown comprises four tracks that are secured to deck areas of the catamaran (known here as "deck tracks"). These include a front track (the "bow track") track, a rear track (the "stern track") and two side tracks (the "port track" and "starboard track").

The port and starboard tracks shown are linear and are generally parallel with one another. Similarly, the bow and stern tracks are also linear and are generally parallel with one another. The bow and stern tracks are at right angles to the port and starboard tracks. (Other arrangements are however possible, including curved tracks and/or continuous tracks. It is also possible to provide further tracks, e.g. for use with additional sails. One such track is shown in front of the stern track, but is not in use in the embodiment shown in the figures.)

Each deck track is shaped to receive a slider that can slide along the track until it reaches a stop. Stops are provided for each track, with a stop at each end so as to constrain the movement of the sliders and thereby to prevent them sliding off the tracks.

The port and stern tracks run substantially along the length of the catamaran. Similarly the bow and stern tracks run substantially along the width of the catamaran. This allows the sliders to move significant distances and allows great flexibility in sail positioning, as will be described later. Indeed it is preferred that port and starboard tracks along at least 50%, more preferably at least 60%, at least 70%, at least 80% or at least 90% of the length of the vessel.

Similarly, it is preferred that bow and stern tracks run along at least 50%, more preferably at least 60%, at least 70%, at least 80% or at least 90% of the width of the vessel.

In some circumstances the tracks may even extend beyond the normal width or length of the vessel. For example they may be mounted to a platform that overhangs the hulls of the catamaran.

Turning now to the mast, it has a base that is slidably mounted in a manner that allows it to be slid towards either the port or starboard sides of the catamaran from a central position. This is achieved by connecting the base to a slider that is located on the bow track. This track is therefore also referred to herein as the "mast base track".

The mast is also provided with two mast supports. One of the supports (the "port support") has its base located towards the port side of the catamaran. The other support (the "starboard support") has its base located towards the starboard side. The bases of these supports are also connected to sliders. These are located on the port and starboard tracks respectively. The tops of the port and starboard supports are operably connected with the mast in a manner that allows both sliding and pivoting, as will be discussed later.

The mast supports function to support the mast in a wide range of different possible orientations and angles to the wind. They can provide support both under tension and compression (depending upon the positioning of the sail and the wind speed and direction). This is very different form conventional rigging in the form of ropes that function under tension but provide no support under compression.

The movement of the supports and mast can be controlled by a rope and pulley system, which allows an operator to move them as desired. Figure 11 illustrates this by showing two ropes that are attached to the base of a support and can be used by an operator to pull the support in different directions, depending upon which rope is chosen.

When the supports and mast have been moved to desired positions, they can then be releasably secured in place in these positions. This can be done for example by using jam cleats (see Figure 13). Alternatively any other releasable securing means can be used (e.g. tying, releasable clamps, a ratchet system, etc.). The catamaran may be provided with a solid platform that supports an operator when operating the vessel. Alternatively, as is frequently the case with multihulls and as shown in the figures, support may be provided via a resilient sheet (e.g. a tarpaulin) or mesh that is secured between the hulls.

The operator is typically located in a central position behind the mast at a location where the boom can be controlled. This can be considered to be the "operator position" in the embodiment shown in the figures.

When in this position the operator should be able to control the catamaran during normal sailing conditions, allowing in some cases for a limited degree of movement of the operator to either side. (In a preferred embodiment however the controls are positioned so that they can be operated from a single operator position, without the operator needing to move substantially.)

Thus, for example, a plurality of ropes used to control the mast and supports can converge towards the operator position.

In the embodiment shown in the figures the masts and supports are connected at their bases to sliders via universal joints. The bases also comprise resilient springs (see e.g. Figure 11). These springs allow a degree of flexibility in movement and can increase the compressive and /or of extensive forces that can be endured by the supports. The springs can also be useful in providing a degree of shock absorption, particularly under choppy wave conditions.

[As an alternative to springs other resilient member may be used. For example a piston type system may be used. This may for example be hydraulic or pneumatic. A further alternative is to make the supports out of materials that can flex to a significant degree without breaking. Such materials include various metals and alloys, carbon fibre, laminates, other composite materials, resilient woods, etc. Materials with a "memory" that can return to substantially their configuration once an applied force has been removed are particularly preferred. It is even possible, although less preferred, to dispense with springs or other resilient members and for the supports to be consist of rigid members.]

In addition to the deck tracks described earlier, there are also two tracks that are secured to the mast of the catamaran (referred to herein as the "upper mast tracks"). These can best be seen in Figure 10 of the prints. One upper mast track is located closer to the port side than the starboard side of the mast. This is the near track shown in Figure 10 and is referred to herein as the "port upper mast track". The other track that is located closer to the starboard side than the port side is referred to herein as the "starboard upper mast track". This is the far track shown in Figure 10.

It can be seen that both upper mast tracks are located relatively high on the mast, with the centres of the tracks being at least halfway up the mast (see e.g. Figure 1).

Each of the upper mast tracks carries a runner and a plurality of stops (see Figure 10). One stop prevents the runner travelling beyond a given distance up the mast. Another stop prevents the runner travelling beyond a given distance down the mast. If desired the stops may be releasable so that the effective length of an upper mast track can be varied. For example Figure 10 shows each upper mast track to have four stops. In the embodiment shown the upper end of the support is constrained between the second and third stops. However, if desired, these stops can be removed to provide a longer effective track between the first and fourth stops. Furthermore the positioning of the stops can be adjusted. By changing the position of the stops the angle at which the mast can tilt can be adjusted. The stops can however be used to ensure that dangerous angles can be avoided.

Each support is pivotally connected to the mast at the upper end of the support via a universal joint. It is also slidably mounted to the mast via a slider.

Thus the port support shown in Figure 10 is operably linked with the port upper mast track in a manner that allows both sliding and pivoting. Similarly, the starboard support is operably linked with the starboard upper mast track in a manner that also allows both sliding and pivoting.

If desired, one or more of the sliders may be spring loaded (or otherwise biased, e.g. by using a bungee or other resiliently deformable member) so as to provide a degree of resistance to movement along the tracks. This can be useful in reducing excessive movement so as to facilitate smoother sailing. A similar system can also be provided for the sliders that slide along the deck tracks.

As indicated earlier, an operator preferably has control of the mast and of both supports from a single location. The operator also has control over a boom that is attached to the mast. In the embodiment shown the boom is operably connected to a slider that runs along the stern track. This can for example be done via a pulley system (see e.g. Figure 9) or via a bungee.

The boom may be releasably secured in a given position by using a jam cleat (or other releasable securing member). In practice, however, the boom may be moved frequently and the operator may therefore seek to control it primarily by hand without extensive use of jam cleats. Thus it may be free running along the stern track. This allows a high degree of flexibility for moving the boom when sailing, whilst still avoiding excessive swinging of the boom, since the track constrains its movement.

Alternatively the boom may be connected to the slider via an intermediate supporting member or it may even be directly connected to a slider via a universal joint that allows pivoting of the boom.

It will be appreciated from the foregoing description that, when sailing the catamaran, the sail position can be easily and quickly adjusted. Unlike conventional boats, the mast can be moved towards the starboard and/or port sides and can be moved back again (as well as to all positions between the extremes). This allows a great deal of flexibility in positioning the sail so that it can catch the wind in a highly efficient manner. Thus, for example, the centre of the sail can be positioned in a manner that is above the centre of gravity of the boat in a variety off different wind conditions.

The present invention allows the mast can be set vertically as for normal sailing boats but also for it to be angled in manner that can provide a high degree of lift. This can cause the hulls of the catamaran to rise out of the water to some degree and can thereby reduce drag and increase speed. In one aspect of the invention a tracking system using control ropes along the lines illustrated schematically in Figure 16 can be provided.

The system is extremely flexible in allowing a wide variety of positions to be easily and quickly adopted for the mast the supporting supports and the boom. The system also allows the different components to be movably linked. Thus movement of the mast to a given position causes the supports (and preferably also movement of the boom) to move into appropriate positions for the new mast position. This reduces the number of controls required by an operator and makes sailing the vessel much easier. Such a system can facilitate self-tacking, because movement of the mast under given wind conditions can cause the supports (and preferably also the boom) to automatically move to appropriate positions for tacking, without the operator needing to move them.

Turning to Figure 16 in greater detail, partial views of a mast 1, a starboard support 2 and a port support 3 are shown. The supports 2, 3 serve to support the mast 1 in a wide range of different positions.

The bases of the supports 2, 3 and mast 1 are moved by operating a main winch 4 using a handle 5. The winch 4 acts upon control ropes 5. In the view shown the winch 4 is rotated in a clockwise direction as indicated by curved arrow 6. Operation of the winch 4 causes the movement of control ropes 7 along the directions of the straight arrows 8 indicated. The winch 4 can of course be turned in the reverse direction (i.e. the anti-clockwise direction) so as to reverse the direction of movement of the control ropes 7 from that indicated in the figure by the straight arrows 8. This allows the movement of mast 1 and supports 2, 3 to be reversed. It also allows fine adjustments.

The winch 4 is desirably securable at any desired position of rotation, so that once a desired orientation has been achieved for the mast 1 and supports 2, 3 the winch 4 can be prevented from further rotation. The mast 1 and supports 2, 3 can then be kept in that general orientation until further adjustment is desired. Lockable winches are of course well known in the art and are preferred for use in the present invention.

It will be appreciated by the person skilled in the art that that the base of the mast 1 moves from port to starboard (or vice versa) along the horizontal axis of Figure 16. The bases of the supports 2, 3 move from bow to stern or vice versa along the vertical axis of Figure 16.

The supports 2, 3 and mast 1 are of course interconnected and therefore move in a synchronised manner. The supports 2, 3, are operably linked to the mast in a manner so as to support the mast in a wide range of positions.

The bases of the port 3 and starboard supports 2 move in opposite directions from another, since they are operably connected by control ropes 7 that move in opposite directions. Both port 3 and starboard supports 2 move at right angles to the base of the mast 1.

Smooth movement of the control ropes 7 is facilitated by free wheel blocks 11, which guide and redirect the ropes 7 as required. (Other low friction means can of course be used as alternatives to free wheel blocks.) Spring fixings 10 are provided to assist in maintaining tension in the system. Stop ends 12 for the control ropes 7 are also provided.

The positioning of control ropes 7 and operably associated components can of course be adjusted for any shape of vessel/arrangement of tracks.

The supports 2, 3 include spring mountings 9. These can acts as shock absorbers/facilitate smooth operation of the system. Low frictions sliders 20 are also provided

The ratio of mast movement to support movement may be varied as appropriate. The system illustrated in Figure 16 is in respect of a ratio of about 2:1 of support movement to mast movement. Other ratios can of course be used, depending upon the layout of tracks and the arrangement of mast and supports.

A simple system is illustrated by Figure 16. It is of course possible to vary the system as appropriate for any given size or shape of sailing vessel.

For example, it may be desired to provide additional control / assistance to aid the movement of the mast and/or supports along the tracks (e.g. for large vessels). Thus, in some instances, one or more gears (e.g. worm gears), pulleys, ropes, hydraulic systems, wires, chains, drives, etc may be used. A power source may be provided (e.g. an electrical power source such as a battery or generator).

The system may even be operably linked to a computer to allow computer control or computer-assistance. If desired the computer may itself be operably linked to a navigation system (e.g. a satellite/GPS navigation system) or may include such a system. The computer may include one or more other inputs such as wind speed, wind direction, tide, wave or current data, maps, data on the speed and direction of the vessel itself, sonar data, weather or climate data, etc.

Turning now to Figure 17 this shows a plan view of a slidably mounted mast 1 and slidably mounted supports 2, 3 upon tracks 21, with the supports being arranged in a symmetrical manner relative the to mast being in a central position relative to a frame 24. The mast 1 and supports 2, 3 move along the tracks 21 upon low friction sliders 9.

The tracks 21 are provided with stops 22 to prevent the mast 1 or supports 2, 3 from moving beyond desired points along the tracks. If desired the stops 22 may be adjustable. The tracks 21 are provide upon a frame 24 that includes two longitudinal members 26 and one or more cross members 23, 25. In Figure 17 one cross member 25 is shown in solid lines and various optional additional cross members 24 shown in dotted lines. Preferably at least two cross members are provided. More preferably at least three are present. It is not essential for each cross members to include a track. It is sufficient for a track 21 to be present on one cross-member (the track 21 for the mast 1). Additional tracks 21 can however be useful for example for lines or other securing means that that can be attached to a boom (not shown).

The mast 1 itself is shown in this embodiment to include tracks 27. The supports 2, 3 are connected to the mast via these tracks. Thus upper parts 27, 28 of the supports 2, 3 run along the tracks (e.g. via castors, bearings, sliders, runners, etc). This can assist in smooth operation of the system and allows a high degree of flexibility.

The frame 24, including associated tracks 21 may be bolted, riveted, clamped or otherwise secured to a deck of a boat. It may be releasable to aid in transportation or storage, as discussed earlier. Turning to Figure 18, this is a front view showing the mast and supports in the position illustrated in Figure 17. Again the symmetrical nature of the arrangement can be appreciated. The mast 1 can be easily moved from the central position shown in this figure towards the port or starboard side so it is in an off-centre position. The supports 2, 3 will then no longer be symmetrically arranged about the mast

This situation (with the mast 1 in an off-centre position) is illustrated by Figures 19 and 20, where the base of the mast 1 is shown being closer to the base of the starboard support 2 than to the base of the port support 3. Here the mast 1 is shown in an angled position, overhanging the port side 3 of the vessel.

The opposite arrangement is of course possible, as are various intermediate positions and further positions for the base of the mast 1 along its track 21.

Tuning now to Figure 21, two hydraulic rams 30, 34 are shown, one at the base of each support 2, 3. Hydraulic pressure is controlled via a hydraulic pump 32, which is operably connected to the rams 2, 3 via hydraulic lines 33.

The hydraulic rams 30, 34 can be used to adjust the length of one or both supports 2, 3. Thus the support(s) 2, 3 can in effect be extended or contracted, as desired, in order to optimise the mast angle for given sailing conditions.

This extension/contraction facility may be further adjusted by moving the connections 27, 28 of the supports 2, 3 to the mast. Thus, for example, by moving the connections 27, 28 further away from point 31 on the mast 1 (referred to herein as an "equilibrium point" or a mid point between the connections) such movement may be enhanced.

At the bottom of each support 2, 3 an optional shock absorber 9 is shown, which may comprise a spring as aforesaid if desired or may be fluid operated. The presence of shock absorbers 9 helps to minimise stress on the system. If desired, a shock absorber 9 may also be positioned at the base of the mast 1 (see earlier Figures 17 to 20). Again this is optional, as indeed is the presence of hydraulic rams 30, 34. [It is also noted that other means for changing the length of the supports when the supports are in situ can be provided, e.g. pneumatic rams, ratchet mechanisms, levers, rack and pinion systems, etc.]

There are of course many further options that may be included, if desired.

As discussed earlier, the catamaran may optionally be fitted with a plurality of hydrofoils (e.g. two or more at each side). These are preferred, because they can increase stability and reduce drag, especially at high speeds. They can also assist in providing increased manoeuvrability at high speeds.

A gyroscope may even be provided that is operably linked to the hydrofoils so that the hydrofoils are automatically adjusted. This can be useful in reducing the risk that the catamaran will tilt at dangerous angles. Preferably the gyroscope is used to keep the boat substantially level under normal sailing conditions. The gyroscope may be operably linked to a computer system, as is known in the art.

As an alternative to a gyroscopically controlled system, an operator may control the hydrofoils. This may, for example, be done via a joystick that is operably linked to all of the hydrofoils, although other controls are of course possible. Indeed, if desired, a separate control may even be provided for each hydrofoil or for hydrofoils at each side of the catamaran.

If hydrofoils are provided it is preferred that they are removable or retractable in shallow water. It is however not essential to use hydrofoils and the vessel will function perfectly well without them in most sailing conditions.

Example 2 Example of other types ofmultihull

As an alternative to Example 1, the invention can be used for other types ofmultihull (e.g. for trimarans, etc).

It is simply a matter of locating the tracks, supports and masts in appropriate positions to take into account the size and shape of the vessel. In the case of a trimaran, for example, the bow and stern tracks may span three hulls rather than two. The longitudinally arranged port and starboard tracks can be located on outer hulls, with the central hull being free of a longitudinal track.

Alternatively, if desired a pre-fabricated frame with the tracks in place may be made initially in a workshop and fitted to the multihull later.

The slidably mounted supports and slidable mast can be positioned appropriately for the size and shape of the vessel. Similarly the height of the supports and mast can be tailored appropriately for the vessel and the sail to be used.

Example 3 Monohulls

As a further alternative to Example 1, the invention can be used for monohulls.

The combination of bow, stern, port and starboard tracks shown for the catamaran in the figures is generally rectangular (see e.g. Figure 9 and Figures 17 and 19). This fits well with the shape of multihulls, where the width is normally fairly constant along the length of the vessel.

In contrast, many monohulls have a high degree of curvature. For example, typical sailing boats are relatively wide in the middle but narrow towards the port and stern. The present invention can however still be used here.

In one embodiment the port and starboard tracks are curved. Preferably the curvature corresponds generally with that of the boat. In contrast, the bow and stern tracks are preferably linear, although they can be curved if desired.

A further alternative is to provide a generally rectangular frame that can overhang the vessel where necessary so as to accommodate a generally rectangular arrangement of tracks, similar to that shown for the catamaran. For example, the frame may extend along the length of the boat (or a substantial part thereof) but may overhang the curved sides of the boat.

Many other arrangements are possible and are within the scope of the present invention. For example a single continuous track may be provided for the monohull (and also for a multihull) and all of the sliders may be located along this track.

Thus the supports and mast can be slid along the same track. Here stops can be provided at various positions along the track if desired. Alternatively a rope and pulley system may be sufficient to constrain the movement of mast and supports as desired.

Here the port support may be constrained to move over a first part of the track; the mast may be constrained to move over a second part of the track; and the starboard support may be constrained to move along a third part of the track.

It should be appreciated that the present invention is not limited to use with small monohulls but can be used with tankers, ocean liners, etc., as discussed earlier. It is particularly advantageous in reducing fuel consumption, which can be very important given high oil prices.

It can be fitted to any desired deck area (or can even overhang the deck).

In a preferred embodiment (which also applies to multihulls) the mast and supports are releasably mounted to the one or more tracks so that they can be easily removed and stowed away when not needed. This can be useful, for example, if it is required to remove the mast and support from a container ship if deck space becomes limited and it is desired to place a container at a position occupied by the mast and supports.

A releasable mast and releasable supports are also useful in any event for portability, especially if it is desired to move a boat by road. Any suitable release means can be provided (e.g. quick release pins, releasable locks, etc.). Preferably a releasable boom is also provided.

Example 4 Alternatives to sliding mast and supports

It is not strictly necessary for the mast and supports to slide, as long as they can be moved to desired positions for supporting a sail and taking advantage of prevalent wind conditions.

For, example the masts and support may be moved using a conveyor system. Alternatively, a rack and pinion system may be used.

In a further alternative one or more devices that extend and retract in a controllable manner may be used to move the mast and/or supports as desired. Such devices include pistons, hydraulic rams, telescopic arms, etc.

There are of course many different alternatives and all are within the scope of the invention. Glossary

Various terms used herein will now be described in further detail below for the avoidance of doubt:

"Sailing Vessel"

The term "sailing vessel" is used herein in a broad sense, so as to indicate any mode of transportation with a sail or other form of wind propulsion (e.g. a kite) that can be carried or supported by a mast.

It therefore covers water-borne vessels such as ships and boats for example.

It can even cover large vessels such as tankers, ferries or liners that may be fitted with a sail or other form of wind propulsion so as to reduce fuel consumption. It includes monohulls or multihulls.

It includes vessels with or without hydrofoils.

It even includes modes of transportation that that may be used on land. For example it includes sand yachts and land yachts. These are sometimes used to catch the wind and to race over beaches or other areas of open ground.

The main application of the present invention is however in respect of water-borne vessels "Rigging"

This term is used herein to refer to components used to control the positioning of a sail. The components may include rope, pulleys, etc

"Slidably mounted"

This includes any mounting that is adapted to be slid. It may for example comprise a low friction material or coating, or may comprise one or more bearings, wheels, castors, or runners. Sliding preferably occurs over one or more tracks, although embodiments in which no tracks are present are also within the scope of the invention.

"Movably mounted"

This includes a mounting that is arranged for any type of movement. It is therefore not limited to sliding. It includes for example a mast or support that is mounted in a manner so that it can be moved using a hydraulic system to push or pull it to a desired position.

Claims

1. A sailing vessel comprising a mast that is movably mounted to the vessel in a manner that allows it to be moved during sailing from a central position to a position located more closely to the port side or to the starboard side of the vessel.

2. A sailing vessel according to claim 1 comprising at least one support for the mast that is movably mounted to the vessel; wherein the support is operably connected to the mast and the base of the support is mounted to the vessel in a manner that allows it to be moved during sailing in a different direction from the direction in which the mast is moved.

3. A sailing vessel according to claim 2; wherein the base of the at least one support is mounted in a manner allowing it to be moved along an axis that is substantially at right angles to an axis along which the mast can be moved.

4. A sailing vessel according to any preceding claim; wherein the at least one support can support the mast when the support is under compression or is under extension.

5. A sailing vessel according to claim 4; wherein the at least one support is resiliently deformable or comprises a part that is resiliently deformable.

6. A sailing vessel according to claim 5; wherein said part is a spring.

7. A sailing vessel according to claim 5; wherein the spring is located at the base of the at least one support.

8. A sailing vessel according to any of claims 2 to 7; wherein the base of the mast and the base of the at least one support are slidably mounted so that they can be slid into desired positions.

9. A sailing vessel according to any preceding claim; wherein the at least one support is pivotally and/or slidably mounted to the mast.

10. A sailing vessel according to claim 9; wherein the at least one support engages the mast at a position at least halfway up the mast.

11. A sailing vessel according to any of claims claim 2 to 10, comprising a plurality of said supports.

12. A sailing vessel according to any of claims 2 to 11 , comprising first and second supports, with the base of the first support being located towards the port side of the mast and the base of the second support being towards the starboard part of the mast.

13. A sailing vessel according to any preceding claim; wherein the base of the mast and/or the bases of the one or more supports are mounted in a manner allowing them to each be moved through a distance of at least 1 metre (from one extreme to the other).

14. A sailing vessel according to any preceding claim wherein the mast and/or the one or more supports are slidably mounted to one or more tracks.

15. A sailing vessel according to claim 14; wherein one or more low friction members, bearings, wheels, castors, or runners or used for slidable mountings.

16. A sailing vessel according to claim 14 or 15; wherein there are separate tracks for each of the one or more supports and for the mast.

17. A sailing vessel according to claim 16; wherein there are two supports and the tracks for the two supports are substantially parallel to one another.

18. A sailing vessel according to claim 16 or claim 17; wherein the track for the mast is located substantially at right angles to the tracks for the supports.

19. A sailing vessel according to claim 14 or 15; wherein there is a single track for the mast and the supports, with the mast and supports being located at different positions along the track.

20. A sailing vessel according to any preceding claim comprising one or more releasable retainers for retaining the one or more supports and/or the mast in desired positions, until it is desired to move them.

21. A sailing vessel according to any of claims 1 to 20 that is a monohull.

22. A sailing vessel according to any of claims 1 to 20 that is a multihull.

23. A sailing vessel according to any preceding claim that comprises a plurality of hydrofoils.

24. A sailing vessel according to any preceding claim that comprises at least four hydrofoils

25. A sailing vessel according to claim 23 or 24; wherein each hydrofoil can be moved independently; or wherein there is at least one group of hydrofoils that can be moved independently of another group.

26. A sailing vessel according to claim 25; wherein one group of hydrofoils is on the port side of the vessel and the other group is one the starboard side of the vessel.

27. A sailing vessel according to any of claims 23 to 26; wherein a gyroscope is used to control the hydrofoils.

28. A sailing vessel according to any of claims 23 to 27; wherein a computer is used to control the hydrofoils.

29. A sailing vessel according to any of claims 23 to 26; wherein the hydrofoils are manually controlled.

30. A sailing vessel according to claim 29; wherein the hydrofoils are controlled using a manually operated joystick.

31. A method of sailing comprising moving a mast and moving one or more supports associated with the mast to desired positions.

32. A method according to claim 31 ; wherein the mast and supports are movably mounted to the sailing vessel.

33. A method according to claim 31 or 32; wherein the mast and supports are slidably mounted to the sailing vessel.

34. A method according to claim 31 or claim 32; comprising moving the mast and moving two supports at each side of the mast until the sail is at a desired orientation for sailing under given wind conditions.

35. A method according to any of claims 31 to 34; wherein the method involves releasably retaining the mast and/or supports in desired positions until it is desired to move them again

36. A method according to claim 34; wherein the desired orientation is one on which the centre of a sail that is attached to the mast is above a centre of gravity of the sailing vessel.

37. A method according to any preceding claim wherein the vessel comprises hydrofoils and the hydrofoils are used to control the stability of the vessel.

38. A kit comprising a mast for a sailing vessel and one or more supports for supporting the mast under compression or tension; said kit optionally comprising one or more tracks that are shaped to allow the mast and supports to slide along the track(s) when the mast, supports and tracks are attached to the vessel.

39. A kit according to claim 38, further comprising one or more of the following: a) one or more sliders b) fixings for attaching the tracks to the vessel c) instructions for use in assembling the kit d) one or more further tracks for attachment to the mast

40. A kit according to claim 39, further comprising a plurality of hydrofoils.

41. A kit according to claim 40 further comprising one or more controls for controlling said hydrofoils.

42. A kit according to claim 40 or claim 41 , further comprising a gyroscope.

43. A method comprising using a kit according to any of claims 38 to 42 to modify a vessel.

44. The invention substantially as hereinbefore described, with reference to the accompanying examples and/or drawings.