Method for making a submersible surface with antifouling protection

Abstract

A method for manufacturing a submerged surface, such as the hull of a marine vessel or a submerged grate or conduit, uses particles that are electrically conductive and disposes those particles on the exposed surface. The particles are held in, place by an electrically conductive composite material, such as a conductive gel coat, and a charge distribution layer is used to spread the current through all parts of the conductive outer surface.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is generally related to the prevention of fouling by marine microorganisms on submersed surfaces and, more particularly, to a method for making an electrically conductive surface which efficiently and effectively conducts current in contact with water to affect a characteristic of the water at the boundary layer in contact with the submerged surface.

2. Description of the Related Art

Those skilled in the art of marine vessels and marine propulsion devices are aware of the disadvantages associated with the growth of marine organisms on submerged surfaces, such as boat hulls. These disadvantages are also inherent with regard to other submerged surfaces, such as water intake grates. One method for inhibiting the growth of microorganisms on submerged surfaces is to provide a biocidal agent that is used on the surface. Other methods use electricity to induce the creation of chlorine bubbles in salt water applications or change the pH of the water immediately proximate the submerged surface in fresh water applications. The creation of chlorine or increased acidity near the submerged surface typically uses an electric current to induce the chemical reaction which results in this beneficial effect. However, difficulty has been experienced in providing the necessary structure which is both electrically conductive and sufficiently robust to withstand many repeated cycles of current flow which is able to produce the desired results.

British patent 2,222,832, which issued to Andoe and was published on Mar. 21, 1990, describes a method of protecting the hulls of marine vessels from fouling. The method comprises measuring the surface configuration and shape of the hull (e.g. by running a computer mouse over the hull), cutting strips of predominately copper foil material corresponding to the configuration of the hull which includes at least one structure thereon made of a metal of dissimilar composition to the foil material, applying the strips in overlapping relation but spaced from at least the structure, and smoothing and rolling a roller device over the strips to adhere the strips to the hull. A cathodic protection system is also applied. An adhesive with anti-fouling properties is used.

U.S. Pat. No. 4,428,989, which issued to Marshall on Jan. 31, 1984, describes an anti-fouling and anti-sliming gel coat. A polymeric composition contains copper flakes in sufficient quantities to render the entire thickness of the polymeric composition electrically conductive. The copper flake is treated to remove oxides and reacted with conventional epoxy resins modified with an epoxidized polyol. The formulation not only exhibits outstanding anti-fouling properties but also exhibits anti-sliming properties. The composition is useful as a gel coat and when utilized on ships, boats, and other watercraft, a vessel results which requires no additional anti-fouling or anti-sliming treatment for several years. The composition can also be used to great advantage as a liner for pipes and conduits used to transport salt or freshwater where fouling of the pipes is a problem.

U.S. Pat. No. 5,192,603, which issued to Slater et al. on Mar. 9, 1993, describes a protection system for substrates against aquatic fouling. It comprises coating the substrate with an elastomeric undercoat and with a topcoat of a room temperature vulcanisable silicone rubber. The elastomeric undercoat is generally harder than the room temperature vulcanisable silicone rubber foul resistant top coat. The abrasion and tear resistance of the silicone rubber foul resistant layer is markedly increased by the use of the elastomeric undercoat.

U.S. Pat. No. 5,354,603, which issued to Errede et al. on Oct. 11, 1994, describes an anti-fouling/anti-corrosive composite marine structure. The structure comprises a marine substrate having adhered to at least a portion of its surface a layer of a water permeable composite article comprising a non-woven fibrous web having entrapped therein active particulate to provide the marine substrate with protection against at least one of fouling and corrosion. Underwater surfaces such as ship hulls, buoys, docks, intake pipes, etc., can be protected against marine growth and corrosion by adhering thereto the composite sheet article of the invention.

U.S. Pat. No. 6,173,669, which issued to Staerzl on Jan. 16, 2001, discloses an apparatus and method for inhibiting fouling of an underwater surface. The system comprises two conductive surfaces and a device that alternates the direction of electric current between the two surfaces. The current is caused to flow through sea water in which the two surfaces are submerged or partially submerged. A monitor measures the current flowing from one of the two conductive surfaces and compares it to the current flowing into the other conduction surface to assure that no leakage of current of substantial quantity exists.

U.S. Pat. No. 6,209,472, which issued to Staerzl on Apr. 3, 2001, discloses an apparatus and method for inhibiting fouling of an underwater surface. The system provides an electric current generator which causes an electric current to flow proximate the underwater surface. A source of power, such as a battery, provides electrical power to the electric current generator. The flow of current passes from the underwater surface through water surrounding the surface or in contact with the surface, and a point of ground potential. The point of ground potential can be a marine propulsion system attached to a boat on which the underwater surface is contained.

U.S. Pat. No. 6,514,401, which issued to Chyou et al. on Feb. 4, 2003, describes an anti-fouling system. The system is adapted to be used for an underwater structure immersed in seawater. The anti-biofouling system includes a conductive layer, comprising carbon fiber, graphite powder and binder, formed on a surface of the underwater structure for serving as an anode, a cathode, and a power supply for providing a current, thereby performing an electrolytic reaction for the anti-biofouling system such that a fouling organism is prohibited from attaching to the surface of the underwater structure.

U.S. Pat. No. 6,547,952, which issued to Staerzl on Apr. 15, 2003, discloses a system for inhibiting fouling of an underwater surface. The surface is combined with a protective surface of glass in order to provide an anode from which electrons can be transferred to seawater for the purpose of generating gaseous chlorine on the surface to be protected. Ambient temperature cure glass (ATC glass) provides a covalent bond on an electrically conductive surface, such as nickel-bearing paint.

U.S. Pat. No. 6,973,890, which issued to Staerzl on Dec. 13, 2005, discloses a self-adaptive system for an apparatus which inhibits fouling of an underwater surface. A system is provided which automatically calibrates a marine fouling prevention system. It responds to movement between fresh and saltwater bodies of water, detects damage to the hull or other submerged surface, and responds to the use of the fouling prevention system with different sizes of marine vessels.

U.S. Pat. No. 7,025,013, which issued to Staerzl et al. on Apr. 11, 2006, discloses a multilayered submersible structure with fouling inhibiting characteristics. The structure has an outer coating that is disposed in contact with water in which the structure is submerged, a current distribution layer or charge distribution layer, an electrical conductor connectable in electrical communication to a source of electrical power, and a support structure. By selectively energizing the current distribution layer, or charge distribution layer, chemical and ionic changes can be caused in the water immediately adjacent the outer coating or layer to inhibit the growth of marine organisms on the outer surface of the submersible structure.

U.S. Pat. No. 7,131,877, which issued to Staerzl on Nov. 7, 2006, discloses a method for protecting a marine propulsion system. An electrically conductive coating is provided on a housing structure of a marine propulsion system. By impressing a current on the electrically conductive coating, which can be a polymer material, the housing structure is used as an anode in a cathodic protection system. In addition, the use of the electrically conductive coating on the housing structure as an anode inhibits the growth of marine fouling on the outer surface of the housing structure by forming chlorine gas in a saltwater environment and by forming an acidic water layer near the surface in a non-saltwater environment.

The patents described above are hereby expressly incorporated by reference in the description of the present invention.

In fouling prevention systems that utilize electric current to change the characteristic of the water immediately adjacent the submerged surface, it is necessary to provide a surface which is electrically conductive and which is robust. Since most binders, such as polymer matrices, are not sufficiently electrically conductive for these purposes, higher current densities are necessary to achieve the desired results of producing chlorine in saltwater environments or changing the acidity of the water in freshwater environments. The use of higher current magnitudes reduces the expected electrically conductive life of the submerged surface. In the production of marine vessels having this capability of generating chlorine on the submerged surface, or changing the acidity of the freshwater near the submerged surface, it is necessary to manufacture the watercraft in an efficient and effective manner which also produces an electrically conductive surface that is robust and can withstand many current conducting cycles during its life.

SUMMARY OF THE INVENTION

A method for making a submersible surface which is resistive to fouling, in accordance with a preferred embodiment of the present invention, comprises the steps of providing a layer of electrically conductive composite material and disposing a coating of an electrically conductive particulate on a surface of the layer of electrically conductive composite material which is exposed to water when the submersible surface is disposed in a body of water.

In a preferred embodiment of the present invention, the method can further comprise the steps of providing a mold, disposing a layer of a temporary holding agent to an inner surface of the mold, spraying the coating of the electrically conductive particulate onto the layer of the temporary holding agent, and spraying the layer of electrically conductive composite material onto the coating of the electrically conductive particulate. In one embodiment of the present invention, the method further comprises the steps of disposing a charge distribution layer onto the layer of electrically conductive composite material. The charge distribution layer can be a carbon fiber mat in one embodiment and can comprise a layer of electrically conductive particulates sprayed onto the electrically conductive composite material in an alternative embodiment. The method can further comprise the step of disposing at least one electrical conductor in electrical communication with the charge distribution layer and attaching a support structure to the layer of electrically conductive composite material. In one embodiment of the present invention, the method further comprises disposing a layer of insulative composite material between the layer of electrically conductive composite material and the support structure.

In the embodiment described immediately above, the electrically conductive composite material can be an electrically conductive gel coat material. The temporary holding agent can be a mold release agent. At least one electrical conductor is disposed in electrical communication with the charge distribution layer and, in a particularly preferred embodiment of the present invention, the electrical conductor is a strip of carbon fiber. The support structure can comprise a layer of fiberglass material. The layer of insulated composite material can comprise an electrically non-conductive, or electrically insulative, gel coat.

Many of the steps described above are particularly applicable to the production of watercraft that comprise fiberglass hulls which are manufactured by using a mold and then successively disposing various layers into the mold until a complete watercraft hull is manufactured. The finished hull is then removed from the mold. However, it should be understood that the present invention can also be used in association with metal hull marine vessels, such as ships. In that case, the structure is produced in a generally opposite sequence, beginning with the electrically conductive metal hull and providing sequential layers until the outermost surface, which is contact with the body of water in which the marine vessel is operated, is completed.

The method of the present invention, can therefore comprise the steps of disposing an electrically insulative coating on an electrically conductive hull of a marine vessel, disposing the layer of electrically conductive composite material onto the electrically insulative coating, and spraying the coating of electrically conductive particulate on the surface of the layer of electrically conductive composite material. It can further comprise the step of pressing the coating of the electrically conductive particulate into the surface of the layer of electrically conductive composite material. This pressing step can comprise the step of using a roller to press the coating of the electrically conductive particulate into the surface of the layer of electrically conductive composite material.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully and completely understood from a reading of the description of the preferred embodiment in conjunction with the drawings, in which:

FIG. 1 is a schematic representation of a marine vessel made in accordance with a preferred embodiment of the present invention;

FIGS. 2A-2G show successive steps in manufacturing a marine vessel in accordance with one embodiment of the present invention; and

FIG. 3 shows a hull made in accordance with a second embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Throughout the description of the preferred embodiment of the present invention, like components will be identified by like reference numerals.

FIG. 1 is a highly schematic representation of a marine vessel 10. The hull of the marine vessel 10 has a portion A which is typically located above the water line 12 and a portion B that is typically below the water line 12 or is frequently wetted during operation of the marine vessel. On the hull of the marine vessel 10, the portion B is the location where the conductive surface provided by the method of the present invention is typically applied. It comprises an outer surface which is conductive and a plurality of electrical conductors 18 which help to conduct current from a source of power, such as the battery 20, and an electrical controller 22 which controls the application of electric current to the hull surface 16. As schematically shown in FIG. 1, a plurality of wires 24 are connected to the electrical conductors 18 to facilitate this distribution of current to the wetted surface B of the hull.

An important purpose of the present invention is to assure that the wetted surface of a submerged object is uniformly conductive across the surface. In other words, one of its intended functions is to avoid concentration of highly conductive material in one portion of the submerged surface with other portions of the submerged surface being more resistive. When this deleterious condition exists, certain portions of the submerged surface carry a significantly higher proportion of electric current than the more resistive portions and this non-uniformity of current conduction can lead to oxidation of those portions of the submerged surface which carry the higher current load. Although other benefits are achieved from the method of the present invention, the uniformity of conduction is an important result that can be achieved from the use of the present invention.

The present invention can be applied in two distinct ways. One method is intended to produce a boat which is manufactured through the use of a mold, as is the case in many fiberglass boats. An alternative application of the present invention can be used in the manufacture of boats or slips having metallic or electrically conductive hulls. Both embodiments of the present invention will be described below.

FIGS. 2A-2G are configured to show the sequential steps used to perform the method of the present invention when manufacturing a marine vessel that is made using a mold.

FIG. 2A shows a partial section of a mold 30 having a surface 32 against which a marine vessel will be constructed and subsequently removed from the mold 30. A mold release material 34 is sprayed onto the surface 32 to facilitate the later removal of the completed boat after the manufacturing process associated with the mold 30 is complete.

FIG. 2B shows the section of the mold 30 with a thin layer 40 of the mold release material 40 disposed on the surface 32. It should be understood that, in FIGS. 2A-2G, the relative thicknesses of the layers are not shown to scale because of the extremely thin dimensions of some of those layers. As an example, the layer 40 of the mold release agent is very thin and primarily serves to prevent later layers from permanently clinging to the surface 32. As will be described below, the mold release agent of layer 40 also serves as a temporary holding agent in a later step of the present invention. After the mold release material 40 is sprayed onto surface 32 as described above, an electrically conductive particulate 44 is sprayed onto the layer of the temporary holding agent 40 which is on the surface 32 of the mold 30.

FIG. 2C shows this coating 48 of the electrically conductive particulate 44 disposed on the layer 40 of the holding agent, or mold release material. The mold release material 40 serves an important purpose of retaining the electrically conductive particulate in place on the surface 32 of the mold 30 during the following step. The electrically conductive particulate material can be carbon or graphite particles, such as a powder or nanotubes. Alternatively, the electrically conductive particulate matter can be any other small particles of a conductive material. This material can be powdered conductive ceramic or other electrically conductive material. In FIG. 2B, this electrically conductive particulate material 44 is shown being sprayed onto surface 40 with a spray gun 50. Alternatively, the layer or coating of the electrically conductive particulate material can be applied by hand (e.g. by dusting) against the temporary holding agent 40 which, as described above, can be a mold release agent. The conductive powder, or electrically conductive particulate material 48, is retained by the temporary holding agent 40 during subsequent steps of the method of the present invention.

FIG. 2D shows the structure described above after a layer of electrically conductive composite material 56 is applied over the retained layer of electrically conductive particulates, such as graphite or carbon powder or conductive nanotubes. The layer of electrically conductive particulates 48 is covered by the electrically conductive composite material 56, such as conductive gel coat, to form a conductive structure with the electrically conductive particles in layer 48 adhering to the outermost portion of the electrically conductive composite material 56.

FIG. 2E shows a subsequent step, after the electrically conductive composite material 56 has been applied to the structure, when a charge distribution layer is disposed on the layer of electrically conductive composite material 56. In one alternative embodiment of the present invention (shown to the left of FIG. 2E), this charge distribution layer comprises a carbon fiber mat 60 which is manually placed against the layer of electrically conductive composite material 56 as represented by the arrows in FIG. 2E. An alternative embodiment of the present invention can spray a second layer of electrically conductive particulates 64 onto the outer surface 62 of the electrically conductive composite material 56.

Later steps of a preferred embodiment of the present invention will be described in conjunction with the alternative embodiment utilizing the carbon fiber mat 60. However, it should be understood that the spraying technique, which provides a charge distribution layer comprising a layer-of electrically conductive particles 64, is also within the scope of the present invention.

FIG. 2F shows a subsequent step of the present invention which comprises the step of placing at least one electrical conductor 18 in electrical communication with the charge distribution layer 60. It should be understood that the illustrations in FIGS. 2A-2G are section views looking down on a portion of the mold and subsequent marine vessel wall. Therefore, the electrical conductors 18 are typically disposed vertically along the sidewalls and transom of the marine vessel. This arrangement is also illustrated schematically in FIG. 1. The purpose of the electrical conductors is to conduct electric current from the controller 22 to the charge distribution layer 60. The purpose of the charge distribution layer 60, in turn, is to distribute the electric current to all portions of the electrically conductive composite material 56. The purpose of the coating of the electrically conductive particulate material 48 is to provide a highly uniform and conductive outer surface for the marine vessel. The improved electrical conductivity of the outermost surface decreases the required magnitude of electric current density (or the time it is sustained) on the submerged surface of the marine vessel. The decreased requirement not only improves efficiency of the system, but increases the expected life of the conductive surface because it provides a uniform current density across the surface of the submerged object. Higher current densities would be much more likely to oxidize the electrically conductive particles in the conductive surface of the hulls and, as a result, shorten the useful life of the conductive surface.

FIG. 2G shows two subsequent steps of the present invention. A layer of insulative composite material 70 and a support structure 72 are provided. The insulative composite material 70 can be a gel coat material, or other polymer material. The support structure 72 can comprise a plurality of layers of fiberglass material that builds up the structure and strength of the hull. In some applications, layers 70 and 72 can be a common structure which comprises a plurality of electrically insulative laminae which, in certain applications of the present invention, can comprise both layers of fiberglass material and layers of liquid epoxy which is used to bind the multiple layers into a solid structure. The insulative characteristic of this structure, particularly layer 70, is that it allows the port and starboard portions of the hull to be electrically insulated from each other. This is particularly useful when the port and starboard portions of the hull are alternatively used as the anode and the cathode in a fouling prevention system. These types of systems are described in detail in U.S. Pat. Nos. 6,173,669 and 6,209,472. In addition, variations of this type of fouling prevention system are described in detail in U.S. Pat. Nos. 6,547,952 and 6,973,890. Other variations of these concepts are described in U.S. Pat. Nos. 7,025,013 and 7,131,877.

With continued reference to FIGS. 2G, it should be understood that the electrical conductors 18 can be strips of a carbon fiber mat. Alternatively, thin metallic conductors can also be used. However, the use of thin carbon mats or graphite to provide the electrical conductors 18 is preferred to other structures because the material is similar to the material of layer 60.

With continued reference to FIG. 2G, it can be seen that one embodiment of the present invention provides a layer of electrically conductive composite material 56 and a coating of an electrically conductive particulate 48 on a surface of layer 56. The coating 48 is exposed to water when the submersible surface is disposed in a body of water. The electrically conductive composite material 56 can be an electrically conductive gel coat material such as that which is commercially available from West Marine and is identified by catalog number 348170. The method of the present invention can further provide a mold 30 and a temporary holding agent 40 which is applied to an inner surface 32 of the mold 30. The coating of electrically conductive particulates 48 can be sprayed onto the layer 40 of the temporary holding agent. The layer of electrically conductive composite material 56 can be sprayed onto the coating of the electrically conductive particulates 48. The temporary holding agent 40 is a mold release agent in a preferred embodiment of the present invention. The present invention can further comprise the step of disposing a charge distribution layer 60 on the layer 56 of electrically conductive composite material. The charge distribution layer 60, as described above, can be a carbon fiber match or a layer of electrically conductive particulates sprayed onto the electrically conductive composite material 56. A preferred embodiment of the present invention can further comprise the step of disposing at least one electrical conductor 18 in electrical communication with the charge distribution layer 60. These electrical conductors 18 can be strips of carbon fiber or a woven carbon mat. The embodiment of the present invention described in FIGS. 2A-2G can further comprise the step of attaching a support structure 72 to the layer of electrically conductive composite material 56 and can also comprise the step of disposing a layer of insulative composite material 70 between the layer of electrically conductive composite material 56 and the support structure 72. The support structure 72 can be a plurality of layers of fiberglass material and the insulative composite material 70 can comprise an electrically non-conductive gel coat.

With continued reference to FIG. 2G, the marine vessel is subsequently removed from the mold 32. Layer 40 of mold release agent, which serves the useful purpose as a temporary holding agent for layer 48, facilitates this removal. The resulting marine vessel has a fiberglass structure with a conductive outer surface. When the present invention is applied to a marine vessel having a conductive hull, such as a ship, a modification is necessary because the marine vessel is not produced through the use of a mold 30 as described above. FIG. 3 shows the sequential steps used to perform an alternative embodiment of the present invention when manufacturing a marine vessel with a conductive outer surface on an electrically conductive hull.

With continued reference to FIG. 3, reference numeral 80 designates a metallic hull of a marine vessel. On an outer surface 82 of the electrically conductive hull 80, a layer of electrically insulative composite material 84 is disposed. Layer 84 can comprise an electrically insulative polymer material, such as non-conductive gel coat. The electrical conductors 18 are disposed directly on the non-conductive gel coat 84 and the charge distribution layer 60 is disposed over the electrical conductors 18. The electrically conductive composite material 56, such as conductive gel coat, is disposed over the charge distribution layer 60 and the electrically conductive particulate material 48 is disposed on the outer surface of the electrically conductive composite material 56. In a preferred embodiment, the electrically conductive particulate material 48 is sprayed onto the outer surface of the electrically conductive gel coat 56.

With continued reference to FIG. 3, it can be seen that the embodiment of the present invention relating to conductive hull vessels comprises the steps of disposing an electrically insulative coating 84 on the electrically conductive hull 80 of the marine vessel, disposing the layer of electrically conductive composite material 56 onto the electrically insulative coating 84, and spraying the coating 48 of the electrically conductive particulate material on the surface of the layer of electrically conductive composite material 56. It should be understood that the charge distribution layer 60 is disposed between layers 84 and 56 along with the electrical conductors 18. It should also be understood that layer 60 can comprise a very thin coating of conductive particles in certain embodiments of the present invention. Therefore, although the embodiment shown in FIG. 3 is described as having layer 56 disposed onto the surface of layer 84, this is meant to include the interposed components identified by reference numerals 18 and 16.

U.S. Pat. No. 6,173,669, described above, discusses the history of fouling prevention which extends back over 2,000 years. These techniques include the use of various materials to inhibit marine growth, including many toxic materials. In addition, various high and low frequency sound waves have been used to discourage fouling of marine vessel surfaces. This history of combating marine growth on submerged surfaces is described in numerous patents that are cited in U.S. Pat. No. 6,173,669. These patents date from 1910 and extend to very recently granted patents. The technique and technology described in published papers and patents fully recognize that electric current can be used to alter a characteristic of the water immediately surrounding a submerged surface. In saltwater applications, this characteristic change typically involves the production of gaseous chlorine. In freshwater applications, this characteristic typically involves the pH, for acidity level, of the water immediately surrounding the submerged surface. The primary purpose of the present invention is to provide an efficient manufacturing procedure that allows the exposed surface of a marine hull, or other submerged device, to be made highly conductive while also being sufficiently robust to have a long useful life. The provision of the electrically conductive particulate material, such as carbon or graphite-powder, at the exposed surface of the submerged layer achieves these purposes. In addition, as described above, the spraying of these conductive particles on the outer surface of an electrically conductive composite material not only improves the conductivity of the structure, but allows lower current densities to be used to accomplish the change in the water adjacent the submerged surface.

Although the present invention has been described in particular detail and illustrated to show several embodiments, it should be understood that alternative embodiments are also within its scope.

Claims

1. A method for making a submersible surface which is resistive to fouling, comprising the steps of:

providing a layer of electrically conductive composite material; and

disposing a coating of an electrically conductive particulate on a surface of said layer of electrically conductive composite material which is exposed to water when said submersible surface is disposed in a body of water; and

pressing said coating of said electrically conductive particulate into said surface of said layer of electrically conductive composite material.

2. The method of claim 1, wherein:

said electrically conductive composite material is an electrically conductive gel coat material.

3. The method of claim 1, further comprising:

providing a mold;

disposing a layer of a temporary holding agent to an inner surface of said mold;

spraying said coating of said electrically conductive particulate onto said layer of said temporary holding agent; and

spraying said layer of electrically conductive composite material on to said coating of said electrically conductive particulate.

4. The method of claim 3, wherein:

said temporary holding agent is a mold release agent.

5. The method of claim 3, further comprising:

disposing a charge distribution layer on to said layer of electrically conductive composite material.

6. The method of claim 5, wherein:

said charge distribution layer comprises a carbon fiber mat.

7. The method of claim 5, wherein:

said charge distribution layer comprises a layer of electrically conductive particulates sprayed on to said electrically conductive composite material.

8. The method of claim 5, further comprising:

disposing at least one electrical conductor in electrical communication with said charge distribution layer.

9. The method of claim 8, wherein:

said at least one electrical conductor is a strip of carbon fiber.

10. The method of claim 8, further comprising:

attaching a support structure to said layer of electrically conductive composite material.

11. The method of claim 10, wherein:

said support structure comprises a layer of fiberglass material.

12. The method of claim 10, further comprising:

disposing a layer of insulative composite material between said layer of electrically conductive composite material and said support structure.

13. The method of claim 12, wherein:

said layer of insulative composite material comprises an electrically nonconductive gel coat.

14-17. (canceled)

18. A method for making a submersible surface which is resistive to fouling, comprising the steps of:

providing a mold;

disposing a layer of a temporary holding agent to an inner surface of said mold;

spraying a coating of an electrically conductive particulate onto said layer of said temporary holding agent;

spraying a layer of electrically conductive composite material on to said coating of said electrically conductive particulate, said coating of said electrically conductive particulate being disposed on a surface of said layer of electrically conductive composite material which is exposed to water when said submersible surface is disposed in a body of water; and

pressing said coating of said electrically conductive particulate into said surface of said layer of electrically conductive composite material.

19. The method of claim 18, further comprising:

disposing a charge distribution layer on to said layer of electrically conductive composite material.

20. The method of claim 19, further comprising:

disposing at least one electrical conductor in electrical communication with said charge distribution layer.

21. The method of claim 18, further comprising:

attaching a support structure to said layer of electrically conductive composite material.

22. The method of claim 21, further comprising:

disposing a layer of insulative composite material between said layer of electrically conductive composite material and said support structure.

23. The method of claim 18, wherein:

said electrically conductive composite material is an electrically conductive gel coat material and said temporary holding agent is a mold release agent.

24. The method of claim 19, wherein:

said charge distribution layer comprises a carbon fiber mat.

25. The method of claim 19, wherein:

said charge distribution layer comprises a layer of electrically conductive particulates sprayed on to said electrically conductive composite material.

26. The method of claim 20, wherein:

said at least one electrical conductor is a strip of carbon fiber.

27. The method of claim 21, wherein:

said support structure comprises a layer of fiberglass material.

28. The method of claim 22, wherein:

said layer of insulative composite material comprises an electrically nonconductive gel coat.

29. (canceled)

30. A method for making a submersible surface which is resistive to fouling, comprising the steps of:

providing a layer of electrically conductive composite material;

disposing a coating of an electrically conductive particulate on a surface of said layer of electrically conductive composite material which is exposed to water when said submersible surface is disposed in a body of water;

disposing a charge distribution layer in contact with said layer of electrically conductive composite material;

disposing at least one electrical conductor in electrical communication with said charge distribution layer; and

pressing said coating of said electrically conductive particulate into said surface of said layer of electrically conductive composite material.

31. The method of claim 30, wherein:

said electrically conductive composite material is an electrically conductive gel coat material.

32. The method of claim 30, wherein:

said charge distribution layer comprises a carbon fiber mat.

33. The method of claim 30, wherein:

said charge distribution layer comprises a layer of electrically conductive particulates sprayed on to said electrically conductive composite material.

34. The method of claim 30, wherein:

said at least one electrical conductor is a strip of carbon fiber.

35. The method of claim 30, further comprising:

providing a mold;

disposing a layer of a temporary holding agent to an inner surface of said mold;

spraying said coating of said electrically conductive particulate onto said layer of said temporary holding agent; and

spraying said layer of electrically conductive composite material on to said coating of said electrically conductive particulate.

36. The method of claim 35, further comprising:

attaching a support structure to said layer of electrically conductive composite material, said support structure comprising a layer of fiberglass material.

37. The method of claim 35, wherein:

said temporary holding agent is a mold release agent.

38. The method of claim 36, further comprising:

disposing a layer of insulative composite material between said layer of electrically conductive composite material and said support structure, said layer of insulative composite material comprising an electrically nonconductive gel coat.

39-42. (canceled)

43. The method of claim 1, wherein:

said pressing step comprises the step of using a roller to press said coating of said electrically conductive particulate into said surface of said layer of said electrically conductive composite material.

44. The method of claim 18, wherein:

said pressing step comprises the step of using a roller to press said coating of said electrically conductive particulate into said surface of said layer of said electrically conductive composite material.

45. The method of claim 30, wherein:

said pressing step comprises the step of using a roller to press said coating of said electrically conductive particulate into said surface of said layer of said electrically conductive composite material.