Hello Jeff,
Just browsing old posts I found this one. My opinion is that it must have been a mistake in location. The giant gold nugget was historically reported to be on the board of ill fated flagship of Francisco Bobadilla fleet called El Dorado. This ship, together with almost whole fleet of more than 30 ships went down really in 1502 but definitely not in Haitian waters. After two days sailing east from Santo Domingo, the fleet was struck by extremely strong hurricane. The disaster occured entering Mona Channel on the southeast tip of La Hispaniola island, today Dominican Republic.
Regards,
Lobo