Over 10,000 man-hours were spent in the waters around New Providence Island, Bahamas, by a unit of British special service troops. Their encounters with dangerous marine fauna are listed together with conditions which released, or failed to release,the attack behavior pattern in shark and barracuda. It was found that the attack pattern was released by jerky rapid movement, and this together with blood in the water was the most dangerous condition. Blood without movement did not release the attack pattern. Factual visual, and auditory effects appeared to be the primary re-leasers, and audition and/or contact alone would release the pattern.