The Easy Exploit Compendium

[Ksheep]

Ring Gate Motorboat
Seal off one side of the first ring and drop and tie the second to a rope. then drop the second off the side of the boat. The water pressure shoots the water out propelling the boat forward.

Except for the fact that Ring Gate specifically says "Up to 100 pounds of material can be transferred each day". So… you can shoot 12 gallons of water out. Hardly enough to jet your boat across the sea. However… it could work if you are on a plane with an extremely short day…