Houseboat Horror.

A rowdy rock group are accompanied by a film crew to desolate Lake Infinity to produce a music video. One night the musicians visit the local pub while the various members of the film crew satisfy their carnal desires with one another aboard the luxurious houseboat they are all staying in. They are so busy they fail to notice that a rampaging lunatic has snuck aboard the boat, and one by one the various characters are brutally slaughtered in a variety of grisly ways.