The item lets you breathe underwater until the oxygen supply ends, which is a relatively long time since it is compressed. It is activated automatically once underwater. If deactivated while underwater, you'll start drowning.
Marine SCUBA Gear Edit
The SCUBA gear appears in Return to Na Pali, in an alternate version known as the Marine SCUBA Gear. What differs from the original version is the regeneration of the oxygen supply, giving it infinite usability. Also, some messages will appear that warn you about the quantity of oxygen left or when the oxygen level is returned to full.
The item acts in the same way as the normal SCUBA Gears found in Unreal, the main difference is that the SCUBA Gear activates automatically once you collect it. A sound of strong breath reverbrating in a mask, heard in Unreal I when underwater wearing the Scuba Gear, will validate that.
- Unreal Tournament