Cyclops

I may have accidentally started another plot hooks thread here.

The USS Cyclops disappeared with all hands in 1918, cementing the idea of the Bermuda Triangle in popular mythology. It's not quite up there with the Marie Celeste because nobody found a deserted ship, and that entire class of ships failed, but it's still a question mark in history.

So who would want to take a ship full of seasoned sailors? Someone who has a battle to fight in water...