Environmental problems posed by metal-based antifouling coatings, in particular those containing organotins, have led to legislation curbing their use and a concomitant increase in interest in the development of nontoxic alternatives. Two main avenues are being pursued: (1) the development of foul-release or easy-release coatings that interfere with the normal adhesion of marine organisms and (2) the isolation of marine natural products that inhibit settlement of potential epibionts on the host organism and accordingly could be incorporated into coatings to inhibit biofouling. This presentation concentrates on the latter option, highlighting similarities in functional groups of some identified compounds and the testing of much simplified structural analogs.