In one aspect, the invention has an object of providing antifouling coating compositions which have high resistance to fouling, in particular, fouling by slime, can form coating films with excellent properties such as strength and rubber properties, exhibit appropriate viscosity (sprayability and coating film surface leveling properties during spray coating) and sagging resistance, and have high storage stability suppressing deteriorations of these properties. To achieve the object, the invention provides an antifouling coating composition including (A) a diorganopolysiloxane having at least two silanol groups in the molecule, (B) an organosilane and/or a partial hydrolyzate condensate thereof having at least two hydrolyzable groups in the molecule, and (C) a pyrithione metal salt. The antifouling coating composition can be prepared from a kit in the form of a multiple-component system including respective packages of a component including the component (A) and the component (C), and a component including the component (B). In the (kit for the preparation of the) antifouling coating composition, the pyrithione metal salt (C) functions as an effective ingredient for achieving excellent antifouling properties, in particular, anti-sliming properties, and also as an effective ingredient for improving storage stability.

The method and system uses ultrasound (US) transducers in contact with an inboard surface underwater portions of marine vessels or structures. By first digitally generating disruptive, multi-frequency, interfering US waveform signals (complex waveforms, typically replicating a Bessel function) and then converting the signals into analog, the transducers generate disruptive, multi-frequency, interfering US waveforms through the underwater portions of the marine vessels and structures which waveforms disrupt unwanted marine growth on the water-side of the vessel or structure. The digital signals, and also the analog signals, are complex waveform signals, typically produced with a Bessel function. The US transducers are either circular membrane transducers or surface transducers. A computer processor coupled to a memory, generates the complex waveform signals fed to the US transducers.

Methods of forming a boat hull include applying an outer polymer layer onto a hull mold, the outer polymer layer being impregnated with a biologically active chemical substance that inhibits biofouling-induced chemical, biological, and bio-proliferative damage. An inner polymer layer is applied onto the outer polymer layer, the inner polymer layer being impregnated with a biologically active chemical substance that inhibits biofouling-induced chemical, biological, and bio-proliferative damage. One or more layers of fiberglass matting are applied on the inner polymer layer, the fiberglass matting being saturated with a polymer selected from one of a group of polymers comprising a vinyl ester polymer, a phthalic unsaturated polyester polymer, and an epoxy polymer.

In a device for repelling organisms causing human damage such as sharks, a tubular member made of a viscoelastic material and a part of the tubular member are provided. A voltage is applied between the built-in power supply device, electrodes provided on a part or all of the outer surface of the tubular member, a string-shaped member having a counter electrode extending from the tubular member, and the electrodes. A switch that turns on and off the energization from the power supply device for power supply, and a joint member that connects the tubular members in a ring shape, and by putting them in water and applying a voltage between the electrodes, sharks that live in water, etc.

The present invention provides antifouling coating compositions having excellent long-term storage stability and provides an antifouling coating composition that can maintain the stable dissolution and antifouling performance of a coating film without causing coating film defects such as cracks in seawater for a long term, such that an antifouling coating film having increased environmental safety can be formed. The present invention provides an antifouling coating composition containing: (A) a triorganosilyl ester-containing copolymer obtained from a mixture of (a) a triorganosilyl (meth)acrylate monomer represented by general formula (1):

##STR00001##

(here, R.sup.1 is a hydrogen atom or a methyl group; and R.sup.2, R.sup.3, and R.sup.4 are the same or different from each other and each represents a C.sub.3-6 alkyl group branched at the α-position or a phenyl group) and (b) an ethylenically unsaturated monomer copolymerizable with the triorganosilyl (meth)acrylate monomer; and (B) calcium sulfate hydrate.

Disclosed are devices, methods and/or systems for use in protecting items and/or structures that are exposed to, submerged and/or partially submerged in aquatic environments from contamination and/or fouling due to the incursion and/or colonization by specific types and/or kinds of biologic organisms and/or plants, including the protection from micro- and/or macro-fouling for extended periods of time of exposure to aquatic environments.

Disclosed are devices, methods and/or systems for use in protecting items and/or structures that are exposed to, submerged and/or partially submerged in aquatic environments from contamination and/or fouling due to the incursion and/or colonization by specific types and/or kinds of biologic organisms and/or plants, including the protection from micro- and/or macro-fouling for extended periods of time of exposure to aquatic environments.

A marine cathodic protection system configured to protect a metal structure exposed to seawater from corrosion. The system includes a first anode provided on or adjacent the protected metal structure at a first position. The first anode is exposed to seawater, is electrically insulated from the protected metal structure, and is formed of a metal having a greater negative potential than the protected metal. The system further includes a second anode provided on or adjacent the protected metal structure at a second position. The second anode is electrically connected to the first anode. The first position is preferably substantially submerged in said seawater such that the protected metal and the first anode cooperate to define a seawater battery configured to apply an electrical current to the second anode, the second anode thus being an impressed current anode.

A marine cathodic protection system configured to protect a metal structure exposed to seawater from corrosion. The system includes a first anode provided on or adjacent the protected metal structure at a first position. The first anode is exposed to seawater, is electrically insulated from the protected metal structure, and is formed of a metal having a greater negative potential than the protected metal. The system further includes a second anode provided on or adjacent the protected metal structure at a second position. The second anode is electrically connected to the first anode. The first position is preferably substantially submerged in said seawater such that the protected metal and the first anode cooperate to define a seawater battery configured to apply an electrical current to the second anode, the second anode thus being an impressed current anode.

A system includes a UV light source and an optical medium coupled to receive UV light from the UV light source. The optical medium is configured to emit UV light proximate to a surface from which biofouling is to be removed once the biofouling has adhered to the protected surface. A method corresponds to the system.