BOAT LOWER HULL

The present invention relates to a boat lower hull.

Boats are known to present a hull, of which that part normally immersed in water is known as the lower hull. The hull can be constructed variously of glass reinforced plastic, metal, wood or other materials.

By way of example, reference will be made hereinafter to a hull with its lower hull constructed of glass reinforced plastic, this being the mostly used system. A layer of gelcoat is applied to the glass reinforced plastic layer to cover, protect and above all to impermeabilize the lower hull, in order to prevent osmosis which could structurally damage the lower hull.

A layer of antivegetative paint is then applied to the gelcoat layer. The antivegetative paint comprises substances that prevent or hinder the attachment of algae, microorganisms, barnacles etc. to the lower hull; this is necessary because foreign elements attached to the lower hull hinder the flow of water along the hull, so worsening the nautical characteristics (speed and manoeuvrability) of the boat.

The antivegetative paint applied to the lower hull is slowly released into the external environment; this means that the antivegetative layer has to be periodically renewed (usually annually) by grounding the boat with all its related costs.

The antivegetative paint contains toxic and poisonous, and hence pollutant, substances. It is on the basis of this principle that the antivegetative paint prevents any formation of life on its surface during the time that it remains effective.

The technical aim of the present invention is therefore to provide a lower hull for boats by which the aforesaid technical drawbacks of the state of the art are eliminated, while improving their hydrodynamic performance.

Within the scope of this technical aim, an object of the invention is to provide a lower hull which achieves high hydrodynamic performance for boats, with consequent reduction in fuel consumption and less atmospheric pollution.

A second object of the invention is to provide a lower hull which does not release toxic poisonous substances into the sea and which more generally is non-pollutant. A third object is to provide a lower hull which prevents or hinders attachment of algae, barnacles, microorganisms, etc.

A fourth object is to substantially reduce the frequency of lower hull maintenance.

These objects are obtained by using a layer of suitably formulated silicone and utilizing its characteristics of antiadherence, slidability, softness and chemical resistance to marine agents.

The technical aim together with these and further objects are attained according to the present invention by a boat lower hull in accordance with the accompanying claims. Advantageously, the lower hull of the invention presents a particularly smooth outer surface in contact with the sea water to facilitate sea water flow.

This enables fuel consumption to be further substantially reduced (or speed to be increased for equal fuel consumption), enables pollution to be reduced and a substantial overall energy saving to be achieved. The lower hull of the present invention also suitably presents very high chemical resistance to the marine environment.

Further characteristics and advantages of the invention will be more apparent from the description of a preferred but non-exclusive embodiment of the boat lower hull of the invention, illustrated by way of non-limiting example in the accompanying drawings, in which: Figure 1 is a perspective view of a boat presenting a lower hull according to the present invention;

Figure 2 is a section through a portion of the lower hull of the boat of Figure 1 ; and

Figure 3 is a section through a different embodiment of the boat lower hull. Said figures show a boat lower hull, in which the boat is indicated overall by the reference numeral 1 and the lower hull by the reference numeral 2.

The lower hull 2 comprises a structure 3 formed of glass reinforced plastic defining the hull, covered externally by a silicone layer 4, applied for example by spraying, by a spatula or a brush; this silicone layer is of constant or variable thickness along the lower hull, for example in proximity to the keel the layer is thicker whereas in proximity to the water line the layer is thinner.

The silicone layer 4 is formed of silicone from the family comprising RTV, LSR, silicone resins, HTV in solution or other resins, suitably formulated.

In a different embodiment shown in Figure 3, the lower hull 2 comprises a layer of primer 5, interposed between the hollow structure 3 and the silicone layer 4.

This primer layer 5 is for example of silane or other type.

Advantageously, the silicone layer 4 could contain antivegetative additive. The molecular structure of the silicone allows gradual release, to obtain lesser pollution than current systems.

The silicone layer 4 provides the lower hull with a surface which in addition to facilitating water flow is also soft.

It has been surprisingly verified that this facilitates water flow, enabling very high speeds to be obtained with very low fuel consumption.

By its nature, the silicone also hinders adherence to its surface by virtue of its natural antiadherence and slidability, hence even if certain algae or microorganisms manage to adhere to the lower hull of the invention, they are immediately detached on starting the boat.

The boat lower hull conceived in this manner is susceptible to numerous modifications and variants, all falling within the scope of the inventive concept; moreover all details can be replaced by technically equivalent elements, In practice the materials used and the dimensions can be chosen at will according to requirements and the state of the art.