The Ocean in Survival 303 is a large body of salt water between Islands. The water itself is undrinkable. It can lead to death via drowning when you stay under it for too long.
There are three ways to traverse the ocean. Firstly, a player can walk across the seabed. This is considered dangerous as, when beneath the top of the ocean, the player loses health. Secondly, a player can swim along the surface of the ocean. Unlike the previous method, the player does not lose health, however, once their swim meter runs out, they begin to quickly lose vitality. If under water for a long period of time, your health meter drops to 50% and if longer, your health meter shall drop to 2% giving you seconds to get onto land and regain health. Thirdly, a player can construct a boat which floats on the top of the ocean, avoiding the negative points of both previous methods.