Main float buoyancy.
CFR · 2024-01-01 · US · Title 14
Each main float must have— (a) A buoyancy of 80 percent in excess of that required to support the maximum weight of the seaplane or amphibian in fresh water; and (b) Not less than five watertight compartments approximately equal in volume.
official document · source cfr-2024 · id 14:§ 25.751