Air Bladder (Subnautica)

The Air Bladder is a tool crafted by using the fabricator.

It is a flotation device that allows the player to reach the surface of the water faster than just swimming to the surface.

Uses
Once equipped, the player can use the Air Bladder to ascend quickly to the surface. This is especially useful in situations where the player is running out of oxygen or needs to escape dangerous creatures. Pressing the right mouse button (RMB) will inflate the Air Bladder, consuming 3 Oxygen but causing the player to rapidly ascend.

Once at the surface, players need to use the right mouse button to deflate the Air Bladder. It is impossible to swim down into the ocean with the Air Bladder inflated.

Speed
A number of tests were run from the depth of 50 meters to determine the speed of swimming to the surface with fins versus using the Air Bladder. With fins, players will average 4.16m/s or 12 seconds to ascend from a depth of 50 meters.

With the Air Bladder, players will average 6.25m/s or 8 seconds to ascend from a depth of 50 meters. (This is also assuming that ascending occurs at the same speed in all biomes.)

Trivia

 * The player can inflate the Air Bladder and then dequip it, and when re-equipped the Air Bladder will still be inflated, cheating the loss of 3 air.