Boats now are filled with water when placed in water. This is probably caused by the rendering code that used to remove the water texture inside of the boat no longer working.
Boats appear to sink in water
boats half-submerged in water
Water goes through boats
Water Texture goes inside boat
The Boats in Water
Boats have water in it
Boats sink and riding them doesn't play a hand animation
water render in boats.
Boat shows water in it when placed in water.
Boats appear to be sunken in water
Entities riding boats, minecarts or other entities are rendered too dark when their hitbox intersects solid blocks