London Lad
Flashlight Enthusiast
Most people have buoyancy at the surface i.e. they tend to float. As they swim down buoyancy decreases and at some point becomes negative, they start to sink.
As a general rule (but not always) the leaner you are the less buoyancy you have and the fatter you are the more you have.
When scuba diving you wear weights to make it easier to swim down and a buoyancy compensation jacket that you can add air too in order to establish 'neutral buoyancy' at the depth you wish to stay at.
Some people who are very lean or densely muscled have a natural negative buoyancy and can scuba without weights.
As a general rule (but not always) the leaner you are the less buoyancy you have and the fatter you are the more you have.
When scuba diving you wear weights to make it easier to swim down and a buoyancy compensation jacket that you can add air too in order to establish 'neutral buoyancy' at the depth you wish to stay at.
Some people who are very lean or densely muscled have a natural negative buoyancy and can scuba without weights.