Aqua - lung
The Angel of Darkness. For information about the very similar item found in Tomb Raider Chronicles, see Aqualung.
The Aqua - lung is an item in The Angel of Darkness found twice in the level The Vault of Trophies.
It gives Lara the ability to hold her breath for a longer period of time while underwater.
Respirators can also be used in a similar way as the Aqua - lung when in underwater.
"For Flooded Environments" 
- ↑ In-game inventory