Exactly my thought. Set them free in a zodiac after disabling the motor. Give them a pint of water each. If that vessel was flying the US Flag, that is an act of war at sea.
After the zodiac gets a few hundred yards out, time for some small arms target practice. Hate to lose a raft but what the hell.
The guys over on arfcom were talking about what a good bachelor party event the pirate problem could be turned into.
Get a few boats, lots of beer, rail mounted full-auto weapons, and have at it.