Reach the deepest possible and then come back to your boat.
Oxygen :
- You can swimp ( jump in ̶m̶i̶d̶a̶i̶r̶ midwater) using 50% of your current tank
- Open the clam with an hermit crab shell to refill your tank
- You have 5 oxygen tanks. Once they are all gone, you’ll drown !!