The diver uses an air tank, which is a tank filled with compressed air. It has a hose that goes from the tank to the mouth, which is held in the mouth by a 'mouth piece'. The tank has a regulator that allows the pressure in the tank to be regulated down for normal breathing.
A SCUBA (self-contained underwater breathing apparatus) tank
a breathing tank! try it its fun! (underwater swimming)
They don't breathe normally on their own.They have to use pressure regulators to breathe naturally, overcoming the extreme pressure deep underwater.A snorkel and oxygen tank help the divers breathe when they are underwater.
Fish use gills to breathe underwater.
I would think they breathe with there mouth underwater.
Fish have gills, that's what helps them breath underwater.
They sometimes find underwater dens that were abandoned by other animals and use that. Others use their strenght to help them make there homes.
True.fish cant breath underwater with lungs.So they use gills to breath underwater.
Some diver use nitrogen to stay underwater for longer but usually compressed air is usedfor those who don't use nitrogen
Scuba - self contained underwater breathing apparatus
Underwater and in Space are the first two that come to mind. I guess you could also say firefighters will wear gas masks in burning buildings.
Humans cannot breathe underwater unaided. It is impossible as we don't have gills. We have to use scuba equipment.