The collective noun is a bubble of scuba divers.
Many people use a SCUBA suit for diving. Sport divers, police divers and some Navy recovery divers.
scuba 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 - self contained underwater breathing apparatus
Scuba Bob's Ocean Quest - 2006 Fearless Divers Scuba Rangers 2-7 was released on: USA: 2007
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 regulators, also called 'diving regulators', are vital for scuba divers to properly obtain oxygen from a tank. Regulators are available for purchase through diving specialty stores such as Prime Scuba, House of Scuba, and Divers Direct.