How does a flotation aid with 1.5kgs of buoyancy hold up a 25Kg person in the water?

Flotsuit by Second SkinsThe flotation manufacturer has done displacement calculations on the floats that demonstrate that 5% will float a kilogram. Therefore 25kg x 5% = 1.25kg will float 25kg.

Let's take the example of a 25kg child. Approximately 80% of the body is water. Water in the body has no weight in water. This brings us down to having to support only 5kg.

25kg X 80% = 20kg and 25kg - 20kg = 5kg weight in water.

However, the flotation aid only has a buoyancy of 1.5kgs. How can it hold up 5kg?

On average our bodies also have 15% fat and fat is lighter than water.

25kg X 15% = 3.75kg and 5kg - 3.75kg = 1.25 kg (Actual weight in water)

Consequently, the average 25kg child only weighs about 1.25kg in water. The 1.5kg of buoyancy in the flotation aid is enough to work as a flotation aid.