Somebody have an idea of the average density (kg/cm³) of animals ? More specifically; aquatic mammals. I know it depends on many factors, and it's not the same value for all animals, but I'm looking for an educated guess.

Somebody have an idea of the average density (kg/cm³) of animals ? More specifically; aquatic mammals. I know it depends on many factors, and it's not the same value for all animals, but I'm looking for an educated guess.

 

Approximately that of water (1g/cm^3, with adjustments for temperature and salinity). It can vary with how much air they have in their lungs, but if the bouyancy differed too much from water it would require excessive effort to either submerge or surface.

It's not just aquatic animals, either. Most animals have densities close to that of water, including humans.