The deeper the diver goes, the higher the pressure is.
Because of very high water pressure.
The collective noun is a bubble of scuba divers.
scuba divers
Many people use a SCUBA suit for diving. Sport divers, police divers and some Navy recovery divers.
Free divers do but scuba divers do not need to. Scuba divers take their air with them and would have no need to hyperventilate.
They swim
seebees
Scuba divers require increased air pressures in their air tanks while diving because the pressure on their bodies increases.
In the Water....
scuba divers
Scuba - self contained underwater breathing apparatus
This is to provide thermal protection usually, though it also protects against getting cuts scrapes or stings from rocks or corals, the main reason is thermal protection
Scuba Bob's Ocean Quest - 2006 Fearless Divers Scuba Rangers 2-7 was released on: USA: 2007