1. At bottom you fill it with fresh water
2. It floats to the surface
3. At the surface you just empty it and remove the fresh water
4. It starts sinking
5. Jump to step 1
1. At bottom you fill it with fresh water
2. It floats to the surface
3. At the surface you just empty it and remove the fresh water
4. It starts sinking
5. Jump to step 1