@pithyrumble
Personally I like how the kraken is set up however I would change its mechanics just a bit.
For starters, the Kraken can only be found in the middle of world events. This means if the world event goes down, a kraken will emerge. When you see a world event, No Kraken will spawn. My idea would be when the new world event spawns, a Kraken will spawn at a random spot and stay there until a player defeats it or the world event is completed or times out. During the time when the world event is down, it will attack whoever lands on its space. When the new world event spawns a kraken will appear at a random spot and not on top of another ship.
Unfortunately if a player sails into a kraken and is in the middle of killing it the kraken will vanish the second the world event goes down. Once a player sails into a kraken that spawns during a world event and kills it, a new kraken won’t spawn until the world event that spawned it goes down and a new world event spawns.