There could be a way to trigger certain small events such as spawns for a Skeleton Ship or a Megalodon, Kraken etc. This could be done by adding them as a voyage for certain factions, or perhaps they can be triggered by using a certain item that might be able to be found in the world/purchased, like a summoning mechanic. Shark bait for the Megalodon, or another kind of special skull to summon a skeleton ship.
This would make it easier to do things like grind for certain commendations, or gain the last little bit of experience needed for an emissary flag to level up.
