The invention relates to sailing boats.

Sailing boats tend to be either small and light or large and heavy since while a small light sailing boat can be stabilised in a generally upright orientation against applied wind forces by shifting the weight of the crew, larger boats need the righting force of a deep and heavy keel to return them to an upright orientation and prevent excessive heeling caused by applied wind forces. Small light boats are unduly cramped for more than one or two persons over an extended time period but large heavy boats must either be kept afloat on a mooring or marina with considerable inconvenience and/or expense or, if brought ashore when not in use, require considerable time and skill to effect recovery from the water, particularly in adverse weather conditions, and further require a sturdy trailer and large and powerful towing vehicle to transport the boat from a slipway to a storage place, particularly if this involves travel on the public highway. For example a sailing boat provided with a keel may have ^0% of its total weight provided in the keel. The deeper the keel and thus the further from the bottom of the hull that the weight is provided in the keel then the greater the righting force provided by such weight when the boat heels over but the more inconvenient it is to load the boat onto a trailer.

According to one aspect of the invention there is provided a lightweight sailing boat having buoyant means provided at opposite sides of the boat generally in the region of gunwales of the boat, such buoyant means being so provided as to engage the water upon heeling of the boat beyond a determined angle and such buoyant means being relatively moveable with respect to the boat thereby to allow the boat to heel beyond said determined angle before the buoyant means starts to exert a significant righting force upon the boat.

Thus the buoyant means may be coupled to the boat by a lost motion mechanical coupling. Preferably the buoyant means are pivotally mounted by coupling them to one end of levers and coupling the other ends of the levers to the boat inboard of the gunwales and providing check means to limit the angle of pivoting of the levers about the inboard pivots.

Each of the buoyancy means may be of angular construction

comprising a first limb extending, in a sailing position, from the pivotal connection to the levers generally horizontally inwardly towards the middle of the boat and a second limb extending from the pivot to the levers generally upwardly and outwardly. In a moored or non-sailing position the buoyant means may be rotated about the pivotal connection to the levers so that the first limb projects downwardly to bring the free end of the first limb into contact with the water and the second limb projects generally inwardly towards the middle of the boat whereby the buoyant means on opposite sides of the boat together with the hull of the boat forms a general trimaran configuration to stabilise the boat against rolling.

According to another aspect of the invention a sailing boat incorporates means whereby wheels and a towing attachment are or may readily be secured thereto whereby the boat may easily be launched or recovered.

The hull of the boat may for example have wells therein in which wheel mounting members can be removably or retractably mounted and a further, generally longitudinally extending, well in which a tow bar attachment can be removably or retractably mounted. Thus the need for a launching trailer with a chassis can be avoided thereby avoiding the often difficult problem, particularly in heavy weather, of aligning a boat with a submerged trolley so that the boat can . be recovered from the water.

The invention is diagrammatically illustrated by way of example in the accompanying drawing which is an elevation from the rear of half of a boat according to the invention.

Referring to the drawing, a boat has a hull 1 which is symmetrical about a centre line 2 and can float in water which has a surface level indicated at 3. The boat may for example be a daysailer of 7 metres overall length with a forward cabin arrangement 4. The boat may be devoid of a keel, may have a lowerable centreboard (not shown) and may be provided with buoyancy means to provide a safety aspect for extreme conditions. The buoyancy means may comprise a buoyant member 5 having a first limb 5a_ and a second limb 5b. connected by pivots 6 to angled levers 7 pivotally mounted by pivots 8 to the hull 1 of the boat.

In a normal sailing position the buoyant members 5 adopt the position shown in solid lines in the drawing. If, during sailing, the

boat s aid heel so that the leeward side buoyant member 5 engages the surface 3 of the water, further heeling will cause the buoyant member 5 and the levers 7 to pivot about the pivots 8 to the position shown in chain dotted lines in the drawing at which the levers 7 have pivoted about the pivots 8 through an angle OC . When the angle OC is achieved, restraint means 9 will restrain the levers 7 from further pivoting and the partial immersion of the buoyant member 5 in the water will apply a righting force to the boat to prevent further heeling and particularly to prevent a complete capsize with total inversion of the boat. By the time the angleoC has been achieved the windage applied to the sails will have been reduced substantially to zero thereby reducing the heeling force and the boat can be restored to an upright position. Latching means 10 would preferably be provided selectively to lock the buoyant member 5 and the levers 7 in the down position on the windward side of the boat, such means preferably being automatically applied. Thus without the weight penalty of a keel, the boat can still be safely sailed without severe risk of complete capsize and inversion.

The boat may be provided with a floodable tank (not shown) in the lower part of the hull whereby the weight of the boat and thus the sailing performance can be controlled.

To stabilise the boat, for example when in harbour and prevent undue rocking, the buoyant members 5 may be pivoted about the pivots 6 to the position shown in broken lines in the drawing in which the free end of the limb 5a. of each buoyant member 5 is immersed in the water below the water level 3 and stabilises the boat by giving it extra width. The boat could be provided with a motor and when used for motoring the buoyant members 4 could be positioned in the dotted line position effectively to give a trimaran configuration.

The upper aft part of the boat, that is to say that part rearwardly of the cabin 4 could be provided as a deck moulding which could be elevated, when desired, to a level substantially equal to or higher than that of the top of the cabin 4 thereby providing a roof which, with for example rolled down curtains, could permit the boat to be converted to a houseboat configuration. The hull 1 of the boat could be provided with wells one on each side towards the rear in which cartridge wheel assemblies could be mounted either removably or retractably, each cartridge wheel assembly mounting a wheel at its lower end, and a longitudinally extending

recess could be provided in the stem of the boat at the bow in which a removable or retractable tow bar could be mounted, thereby providing, with the cartridge wheel assemblies, a three part trailer the chassis of which is effectively formed by the hull of the boat.

The boat of the invention could have its weight reduced to half the weight of a similar size boat, thereby greatly improving its sailing performance, without compromising the safety aspect.