Get scuba divers or boats to tangle old fishing nets on the boats propellers. No need to board the boats. Drag the boats by the tangled nets to port and that is it.
Ship of Fools
Floating Dreck
Shiite Floats
Garbage Scows
Shmucks are Us
Assholes United for Terrorists
Rebels without a Clue
Coney Island Jellyfish Brigade
I'll think of more but this was only thirty seconds worth of brilliance!