Lost!
Bob and his wife Linda accompany his brother Jim on a sailing cruise to Costa Rica, where Jim will start as a missionary. In a terrible storm their boat flips over. Jim believes the accident was a sign from god and throws away their distilling apparatus and food - "You shall not interfere with god's will". However nobody knows they're lost, so no one searches them for weeks.
Directors: Peter Rowe
Writers: Peter Rowe, Thomas Thompson
IMDB: tt0091434