Head Above Water (1996)

Judge George brings his young wife, Nathalie, to a remote island for a vacation. But while George accompanies their only neighbor -- Nathalie's childhood friend Lance -- on a fishing trip, Nathalie spends time with her ex, Kent. When Kent ends up dead the next morning, Nathalie tries to hide the evidence before her husband gets home. After the body is found, the events of the previous night unravel, with unexpected revelations.

Source: TMDb