English

Abstract

An experimental study of the drag and roughness characteristics of a Tin-free Self-Polishing Co-polymer ((SPC))and a non-toxic Foul Release system has been carried out. The drag characteristics were measured in towing tank and water tunnel experiments using different friction planes and in a rotor apparatus using coated cylinders. The measurements show that a typical new application of the Foul Release scheme exhibits less drag than a Tin-free SPC scheme.The roughness characteristics of the two coatings were measured both with a stylus instrument and with an opticalmeasurement system. The measurements show that the texture of the Foul Release coatings is significantlydifferent from SPC coatings.The correlation of drag with roughness is reviewed and the two coatings have been compared with a published database of different antifoulings. Contrary to the other types of coatings, the findings show that the roughness of a newly applied Foul Release scheme will not correlate with its drag when characterised solely by a height parameter, but that it is necessary to take the texture into account.