How do sea otters stay afloat while resting?

Sea otters stay afloat while resting by using their dense, water-repellent fur and air trapped in their undercoat to maintain buoyancy. They often float on their backs, keeping their heads above water, and may anchor themselves with kelp to prevent drifting. Otters also rely on their strong lungs, holding air that aids in buoyancy. These adaptations allow them to rest safely on the water’s surface without expending energy. Floating in groups, known as rafts, provides added security and warmth in their aquatic environment.