Minecraft wiki entry for Drowned, associated text: During the day, drowned swim only to attack players that are swimming in the water with them; otherwise, they stay on the floor of the water body they are in, ignoring players on land or in a boat. Drowned equipped with tridents continue throwing them at the player even after leaving the water. At night or during thunderstorms, drowned swim to the surface and chase players as well as baby turtles, even outside the water, like regular zombies.