Dave the Diver · Diving gear
Air Tank
The Air Tank upgrade line raises listed air capacity from 90 Bar at level 1 to 480 Bar at level 10, supporting longer underwater dives.
How it works
ESTNN lists ten levels with capacities of 90, 115, 145, 180, 220, 265, 315, 370, 425, and 480 Bar. It lists level 1 as free and later levels with Gold costs. The guide says early upgrades increase time available for diving. It gives no oxygen depletion rate or dive duration for each level.
Read the supporting references
Check the edition and source version for patch-specific details. Guide methodology.