A member from my discord server suggested that pirates be added to the game. Like insurgents of the sea, instead of insurgents spawning in coastal provinces pirates should spawn, or perhaps there is a chance that either could spawn. Like insurgents they can spread to other places if left unattended but instead of just traversing across the land they sail to another harbor or coastal city and capture it. They should have their own ships that serve as transport ships, but can also deal a small amount of damage to ships in melee combat, which will give them the ability to harass transport ships but can be easily dealt with using warships. This would add a new layer of relevancy to corvettes. Another feature the pirates might have is once they spawn, they can start raiding other coastal cities within certain provinces. Being raided would have certain penalties like resources lost and/or a morale decrease.
I put on my robe and wizard hat