Disaster #1: Massive Maelstrom - Giant whirlpool that slowly swirl-spawns with thunder and rain (much like At World's End Calypso)
Disaster #2: Giant Tornadoes - Water Tornadoes that sucks up your ship and rains it down when they despawn. Tornadoes are roughly the size of Smuggler's Bay and they all travel in random direction.
Disaster #3: Tsunami - Giant tsunami wave roughly the size of 2 Smuggler's Bay islands spawns in that has a chance of sinking ships that sail in it's moving path.