Creative ideas needed: horror movie. 10 points for best idea?

The boy`s father is haunted by Poseidon`s spirit/ghost and they have to escape. Poseidon kills the girl while she tries to escape on a raft, the others are stuck with the boy.The boy tells he is his son, he DOES NOT BELIEVE that and kills him with a hail( and white sharks), finally the survivors return safe and sound telling the story of the SAD POSEIDON SEED....