Did you see them too?
I popped a quest hut and it was the one where when you unseal some cave a zillion swarm spiders come out and you have them everywhere around. Well, of course some of em ended up in the water. I dont know if they started there or went there by themselves.
You can even see them through the cultural border line, lol
I do recall that at some point before they were on the inaccessible coast tiles, now they appear immobile down there in davy jone's locker.
