A WATERCRAFT SERVING AS AN IMPLEMENT FOR THE PRACTICE

OF THE WATER-SKIING

The subject of the present invention is a watercraft intended for being used as an implement for the practice of the water-skiing.

Usually, the water-skiing is practiced by using as implement a simple substantially plane board which is provided with two seats for the insertion of the skiers feet. The skier, when engaged the board, is immersed in water be¬ cause the board has no sufficient buoyancy for keeping the skier in surface, and he grasps a handle connected to a towline on its turn connected to a tow- boat means. When the towline is dragged by the towboat means, the skier tilts the board in the longitudinal direction in order to be brought to the water surface, and then he proceeds at the surface along a trajectory that, within certain limits, he can choose and modify by acting on the board. In the case of need, the skier can free himself from the towline by abandoning the handle.

Such an implement allows effecting on the water several maneuvers, however to this aim it requires a considerable ability. Especially, the fact that the start is to be effected from an immersed position is seriously disturbing for many skiers, and in any event it requires a great difficulty for the start in view of the great resistance opposed by the water to the advancement of the skiers body, which is about entirely immersed. Also, a consequence of the great re¬ sistance encountered at start is the need to make recourse to a towboat means having a high power, very larger than the moderate power subse¬ quently needed for towing, the skier. Moreover, when the skier abandons the traction handle, he remains engaged with the board, and this can involve dan¬ gers.

The main object of this invention is to provide an implement for the practice of the water skiing which is capable of ensuring to the skier maneu¬ vers possibilities at least equal to those of the known implement, or even more advanced, which is suitable for allowing to effect the maneuvers more easily, and, especially, which allows effecting the start from a position that is not im¬ mersed but floating, and therefore with better comfort and easiness, and al¬ lowing the use of a towboat means of a reduced power.

Another object of the invention is to avoid for the skier the need for continuously keeping grasped a handle connected to the towline, and for being subjected to the entire stress of the traction force, which the skier receives from the towline and transmits to the implement. Another object of the invention is of offering to the skier the possibility of having at his disposal a point of support fixed to the implement, which ren¬ ders considerably easier maintaining the balance and transmitting to the im¬ plement the voluntary actions intended for controlling the advancement tra¬ jectory. Still another object of the invention is to offer to the skier a great secu¬ rity in those cases in which he comes off the implement, either voluntarily or due to a state of emergency.

It is also an object of the invention to improve such an implement in such a manner that it can be adapted in the better way to the height and the weight of the skier, as well as to the conditions of the stretch of water on which the maneuvers are effected.

At least the main object of the invention is attained by an implement for the practice of the water-skiing consisting in a watercraft provided with a platform for resting of the skiers feet, this watercraft having a buoyancy larger than the sum of the own weight of the implement and of the weight of a skier, whereby the watercraft is capable of supporting in floating condition the skiers weight, even in the still condition.

In this way, thanks to the high buoyancy of the implement (buoyancy which is absent in all the known implements for the water-skiing), the skier is permanently supported out of the water by the buoyancy of the watercraft, and this takes place even in still conditions. This renders easier the start and drastically reduces the resistance to the advancement in the start conditions, thus requiring from the skier a modest ability and from the towboat means a reduced power. Preferably, trie watercraft is provided with a upright shaft ending at its upper end with a handle-bar, connected at its lower end to the watercraft and provided, in at least one intermediate point, with at least one means for con¬ nection of a towline.

In this way, the traction force applied by the towline is transmitted di¬ rectly to the shaft and to the implement, without stressing the skier. Moreover, the skier supported by the implement can lean on the handle-bar which, through the shaft, is fixed to the implement, and this allows the skier, on one hand, to easily maintaining its own balance, and on the other hand to more easily transmitting to the implement the voluntary actions, especially of lateral tilt, having the purpose of steering the trajectory along which the implement proceeds.

Preferably, in the normal conditions said shaft is connected to the im- plement through a coupling means suitable for being released.

In this way, when the skier abandons the implement, either because he has fallen into the water or for any other reason, voluntary or not, the im¬ plement, whose balance is disturbed by the absence of the skiers weight, may capsize and then the shaft, subjected to the pull of the towline, disengages from the releasable coupling means which connects the same to the imple¬ ment, and abandons the implement, which remains floating near the skier. Therefore the skiers security is ensured in the best way, because he is not connected to the implement by any link. Subsequently, no difficulty is en¬ countered in inserting again the shaft into the implement, in order to resume the normal operation of the implement. It is of advantage that the shaft with its handle-bar is embodied with buoyancy, whereby it does not sink.

Preferably, the implement has a number of longitudinally aligned cou¬ pling means suitable for receiving the insertion of the shaft. In this way the longitudinal position of the skier on the platform of the implement can be adapted to the weight and height of the skier, as well as to the conditions of the stretch of water on which the implement floats, and in general also to the conditions which are preferred by each skier.

During the run, the traction exerted by the towline is applied at a cer¬ tain distance from the prow of the watercraft, and therefore its directional ac- tion onto the watercraft is reduced and allows that the skiers actions direct the watercraft in a direction which, within certain limits, is independent from the traction direction, whereby the maneuvers are allowed. In view of the better movement freedom of the skier, the control of the watercraft maneuvers is more easy than the control of similar maneuvers with a usual water-skiing board.

Because the directional effect of the towline traction is as much high as the connection point of the towline to the implement is near to the prow, and it is as much low as said connection point is far from the prow, by suitably choosing the insertion position of the shaft in the implement it is possible to attain that the directional effect of the traction is more or less strong. The presence of a more strong directional effect is a hindrance for the maneuvers, however it renders more easy the control of the watercraft on a simple trajec¬ tory, and therefore it is desirable for an inexperienced or not much skillful skier. On the contrary, the presence of a reduced or null directional effect renders the control of the watercraft less easy, but it allows even the more dif¬ ficult maneuvers, whereby it is desirable for a very experienced and skillful skier. By suitably choosing the insertion position of the shaft in the implement it is therefore possible to adapt the implement to the dexterity and the re¬ quirements of different skiers. Preferably, moreover, the shaft has a number of connection means for the towline, situated at different heights over the point in which the shaft is in¬ serted in the implement. Also this feature allows adapting the implement to the conditions of the stretch of water and to the requirements and preferences of different skiers. The shaft may have a telescopic structure and be provided with means for blocking it at different lengths, in order to adapt the implement to the skiers height.

Preferably the shaft along with its handle-bar has buoyancy charac¬ teristics in order to prevent its sinking when it is disconnected from the imple- ment.

It is of advantage that the means for coupling the shaft to the imple¬ ment have retainment means, such as a key, intended for preventing a rotation of the shaft and the handle-bar.

Preferably, the platform formed by the central region of the implement has two side plane regions for a better rest of the skiers feet, and these plane regions may be provided with a covering suitable for preventing a feet slip.

Preferably the lower surface of the watercraft has a transversal down¬ wards directed concavity, and the lower surface of the prow region is upwards curved along the longitudinal direction.

In this way, when the watercraft is laterally tilted by the skier in order to run along a curved trajectory, the thus inclined lower concave surface ef¬ fectively hinders a radial displacement of the watercraft towards the outside, which aims to be caused by the centrifugal force, and therefore renders more easy and precise the trajectory control by the skier. Moreover, the curvature of the lower surface of the prow region, which in the horizontal condition of the implement is directed upwards, in the inclined position takes a horizontal com¬ ponent, and the reaction of the water on this surface applies to the watercraft a force directed towards the curvature center of the trajectory. This force aims positively to tack the watercraft towards the desired direction.

It is suitable that said concavity has a deep decreasing from the re¬ gion wherein the shaft is inserted towards the aft region, wherein this deep may become null.

Preferably, the aft region of the watercraft is provided with a lower fin acting as a rudder for the stabilization of the trajectory.

These and other characteristics, objects and advantages of the subject of this invention will appear more clearly from the following description of an embodiment, forming a non limiting example, with reference to the appended drawings, wherein: Figure 1 shows in a plan view the watercraft of the invention.

Figure 2 shows a side view thereof.

Figure 3 shows a diagrammatic cross section taken along line III-III of Figure 2.

The watercraft is manufactured of a relatively light material having a relatively large volume, in such a manner as to attain the main characteristic according the invention, that of having a buoyancy larger than the sum of the own weight of the implement and the weight of a skier, whereby the floating condition of the charged watercraft is ensured in any condition, even in still condition. Such feature is entirely absent in the known boards used for the water-skiing. To this aim, for example and preferably, the watercraft structure may be embodied by using a glass fiber reinforced resin, hollow or possibly having a filling of expanded synthetic material.

Moreover the watercraft has a special conformation intended to help the maneuvers on water. As it may be observed in Figure 1 , -the watercraft has a prow region 1 , an aft region 2 and a central region 3. Preferably, as it

appears from Figure 1 , the prow region 1 has a relatively large width which helps the stability, and this width decreases in the central region 3 and in the aft region 2. Moreover, as it may be observed in Figure 2, the longitudinal section of the lower surface 10 of the prow region 1 is curved upwards. As it may be observed in Figure 3, the lower surfaces 30 of the central region 3 and 20 of the aft region 2 have, in their transversal sections, a con¬ cavity directed downwards; such feature is contrary to the conformation of the keel of any known watercraft. Preferably, the deep of this concavity of the lower surface is maximum at the front end of the central region 3 and reduces towards the aft region 2, where it may also become null, as it is shown by an interrupted line in Figure 2.

From the whole of the described features it results that, when the wa¬ tercraft steered by the skier is laterally inclined in order to run along a curved trajectory, the concave surface takes a position that opposes to a radial dis- placement of the watercraft towards the outside, which aims to be caused by the centrifugal force, and in this way renders more easy and precise the tra¬ jectory control by the skier. Moreover, the curvature of the lower surface of the prow region, which in the horizontal position of the watercraft is directed upwards, in the inclined position of the watercraft takes a horizontal compo- nent and is considerably immersed due to its width, whereby the reaction of the water against this surface applies to the watercraft a force directed to¬ wards the curvature center of the trajectory, and this force positively aims to tack the watercraft towards the desired direction.

The central region 3, near the buoyancy center of the implement, forms a platform on which the skier rests in the run conditions. In general, at start, the skier will get on the platform in a lowered position, in order to lower the barycentre for easier balance, and will subsequently take an erected posi¬ tion. Preferably, the platform formed by the central region 3 of the implement is provided with two lateral plane regions 9 for a better rest of the skiers feet. These regions may advantageously be provided with a covering suitable for preventing a feet slip ^' ..

The waterboard is provided, near the front end of the central region 3, with a upright shaft 4, which is inserted by its lower end in a coupling means 5 of the implement, and carries at its upper end a handle-bar 6. -This arrange- ment allows the skier to maintain its balance during the run, by grasping the

handle-bar 6, and to easily transmit to the waterboard the voluntary actions by means of which he steers the waterboard in the desired direction. Moreover the shaft 4 and the handle-bar 6 allow the skier to more easily pass from a lowered position at start to an erected position during the run. In order that the shaft and the handle bar are hindered to rotate, preferably the coupling means between the shaft and the implement are provided with a key or a similar means.

In order that it may be adapted in the better manner to the height of the skier, preferably the shaft has a telescopic structure and is provided with means for blocking the same at different lengths.

The shaft 4 has at least one connection means 7 to which is con¬ nected the towline, whereby the traction force of the towline is directly applied to the implement, without stressing the skier.

Advantageously several coupling means 5 for the shaft and several connection means 7 for the towline are provided, whereby every time it is pos¬ sible to adapt the characteristics of the implement to the conditions of the stretch of water, to the height and weight of the skier, as well as to the dexter¬ ity and the preferences of the skier.

It is suitable that the coupling means 5 between the shaft 4 and the region 3 of the implement is releasable. When, voluntarily or by chance, the skier abandons the implement, the balance of this latter is compromised and it may capsize. Then the traction exerted by the towline onto the shaft 4 causes the disengagement of the releasable coupling means 5, and the implement is abandoned in floating conditions near the skier. This latter, if desired, may easily catch the implement and grasp at it. On its side, the shaft along with the handle-bar is preferably made with buoyancy, in order that it does not sink when disengaged from the implement.

Thus, the abandonment of the implement by the skier is done in the conditions of maximum security, because the skier only rests onto the platform of the implement, without any connection which links the skier.

For a better^stability of the trajectory, the implement can be provided in the aft region 2 of a lower fin 8 acting as a rudder.

Of course, if occasionally the skier so prefers, he can avoid using the shaft and the handle-bar, and make use of the implement by grasping with his hands a handle connected to a towline. In this case, he loses a part of the

advantages offered by the implement of the invention, but he maintains the main advantage of starting from a floating position rather than from an im¬ mersed position.

In an inverse case, it is possible to mount a device with shaft and handle-bar on a usual board for water-skiing not having a buoyancy sufficient for keeping in floating condition the board and the skier at still. In this case, however, still are maintained the advantages that the skier is not subject to the traction stress, that he may more easily maintain his balance and that he can more easily and effectively steer the implement. It is to be understood that this invention is not limited to the embodi¬ ment which has been described and shown as an example. Several possible modifications have been stated in the description, and others are available to those skilled in the art. These modifications and others, as well as any re¬ placement by technically equivalent means, may be applied to what has been described and shown, without departing from the spirit of this invention as de¬ termined by the appended Claims.