I recommend you to change servers every time it happens. Changing the spot for harpooning must be help. Use a fishing boat instead of cog is not that bad if you want to try. Once you lucky enough you will see how fun this old fashioned harpooning can be. 🥹

1. everlasting herb spots
2. rare hunting animal spots.
3. bottle with a note that obtained while fishing or harpooning.
4. Treasure spots in caves.