On June 17, 1973, near Key West, Florida, the submersible JOHNSON SEA LINK became entangled in a cable of the wreckage fo the scuttled destroyer U.S.S. FRED T. BERRY after attempting to retrieve a fish trap in the immediate vicinity of the wreckage.   Before the submersible was recovered, more than 33 hours later, two of the four persons on board had died as a result of carbon dioxide poisoning. The probable cause of the accident was the fouling of the starboard spring-loaded moused hoood and other appendages on the submersible, with a cable attached to the aftermost flagpole of the scuttled destroyer.   Contributing factors were inadequacy of the carbon dioxide absorbent system in the dive chamber, and the lack of suitable rescue equipment. Click on the following links for more info. Official USCG Accident Report