Investigations of procedures for the hull cleaning of pleasure boats as an alternative to biocidal underwater coatings

The renunciation of biocide antifoulings is a matter of concern to many national and international committees, authorities and interest groups. This mechanical cleaning alternative connected with a suitable biocide-free coating has been examined including the results taken from step I of the F+E plan. Secondary to plan I, further coatings have been examined with regard to their suitability for mechanical cleaning. Altogether, 27 coatings have been used for performing exposition tests and cleaning tests on steel plates in fresh water and salt water. Those coatings were hard coatings, non-stick coatings based on silicone or wax, biocide-free antifouling coatings based on natural ingredients and coatings with waxes/grease. Furthermore three boats were on site for the test in the yachting harbor "ancora". The boats were covered with a silicone anti-adhesive coating and two biocide-free hard coatings. Concurrent activities were the discussion of the question of a license for an automated cleaning device with the authorities, the estimation of the market potential and a survey about the acceptability. Based on an analysis of the current status of the developments regarding mechanical cleaning devices for pleasure crafts, a rough concept and a fine concept have been developed for an automated cleaning device and a prototype have been built. A technical-economical assessment resulted in an above-water cleaning device as the most suitable cleaning device for Germany.