The gas that makes a body float is the result of putrefaction. Drowned people sink. Diving down to the bottom of the deep end to rescue a large rubber brick was part of our training.
Dead bodies pop up. That’s why burial at sea includes weights.
ETA and why the mafia make you stand in a bucket of quick drying cement before they push you off the pier.
I forgot, it's the air in your lungs that keeps you afloat when alive and when that's gone...
Yeah we did the wearing pajamas and diving for a brick thing.