A group of fun-loving scuba divers called the Sea Dogs find themselves hoodwinked when their biannual dive trip to the Florida Keys is rearranged on an innocent pretense. Their friend Ray Stellar has just inherited a spectacular island off Key Largo, and asks the dive team if they'd rather vacation on his island instead of their normal destination. Eager to save money, the team accepts the free trip. When they arrive on the island, the divers find themselves up to their necks in dirty deeds. To settle his mounting debts, Ray's boss has made a deal with a drug kingpin; and the Sea Dogs unknowingly become involved in the arrangement. The DEA soon shows up, and the Sea Dogs are stalked, used as pawns, and almost get their ship blown up. But their happy-go-lucky attitude and positive perspective see them through, and they manage to thwart the drug kingpin. Just when they thought the bad times were behind them, they stumble onto the lost treasure of Black Beard the pirate. Kidnappings, Black Beard's ghost, and hilarious mishaps plague the Sea Dogs at every turn. Will the Sea Dogs ever find peace and quiet in their lives again, or will their trip be the vacation to end all vacations?