Turtle Shell

Turtle shells are items that are used for brewing or as a helmet to give the player the Water Breathing status effect.

Equipping
If a player is has a turtle shell in their helmet armor slot while out of water, it will give the player the Water Breathing effect for 10 seconds. The effect will continue even if the player goes underwater, if the effect started while they were above water. This essentially gives the player 10 extra seconds of breath underwater.