Jeff & Gloria decide to destroy the boat by sticking a flare in the petrol tank, whilst Danny's onboard. Jeff decides to speed up Danny's demise by bludgeoning him with fire extinguisher. Danny still living slashes Jeff with a blade...critically injuring him. Gloria decides to go ahead with blowing up the boat and sticks a flare into the engine. An oblivious Danny notices Gloria's gone overboard and not noticing the flare, fires up the engines and goes up in flames along with Jeff. The search and rescue chopper (called in earlier on) doesn't spot her due to storm breaking out during the twilight settings. Gloria makes it to one of the islands...but not alive, the opening shot of a female drifting in the shallows of the island shorelines...was obviously her...having drowned.Final sting in the tail...the floating fish eaten head seen by Danny (via the binoculars) bobbing up and down in the distance...was NOT Marco as he is seen very much alive & well AND sunbathing by the pool of the very same couple who were also visting the island Marco, Jeff, Danny and Gloria had anchoured close by to (earlier on in the story).