Dead in the water (2002)

Young, rich, and randy Gloria takes the family motorboat for some fun in the sun off the coast of Brazil. Along with her are her longtime boyfriend Danny, his best friend Jeff, and the son of an important and infinitely influential client, Marcos. It probably wasn't a good idea to take three gorgeous men the same age out on a boat with a bikini-clad beauty who lately has been questioning her relationship with her main squeeze, but it gets even worse than expected. There's tragedy, betrayal, and more tragedy as the faulty value systems of the wealthy brats spin out of control.