KeelHauling
This is a Guide to keelhauling. In order to keelhaul, you need three things:
1: A Keel
2: A Boat
3: A Ninja.
Ninjas are the best fun to keelhaul. They go a nice shade of orange after a few days, and die soon after.
This is the first bit of kit, the keel. It is often included with your ship (presuming it hasn't been looted).
To the keel you should attach a rope, Thus:
You should now get hold of the ninja. This can be difficult, as they often commit sepuku or flip out before keelhauling can begin.
But with practice, you should be able to attach a ninja to the rope.
At this point, start shouting ARRRRRRRRR!!!, and throw sharp things at the ninja. Keep the ship sailing at a speed wherethe ninja is visible below the water but does not surface, to ensure maximum drowning potential!