I feel like the OHOL map needs a new biome. And ocean/lake with brand new items and introducing boats that you can explore with. Some parts of the biome should include a coral reef. This maybe could introduce fishing/swimming. But I also think the player should have a challenge without a boat. So add hypothermia. Once the player is in the water for lets say 40 seconds you will lose food/get hurt. Also for more entertaiment add a shark that will attack humans/boat. Once the boat is hit 3 times the boat would sink. Now Im gonna go over some pros.
PROS- More challenges, more items to make, making docks.
I also think trading would be a cool feature added into this maybe to come aquatic update. Maybe even battles on the sea.
For example you can upgrade your ship to a box with paddles to a full BOAT with cannons and storage. But also would take generations to finish this. This is just a suggestion but I feel like it would be cool.