Breath

Breath is a stat that comes into play when the player is swimming and goes underwater. It is a blue meter that has a duration of three minutes. Players must be careful to return to the surface and replenish their breath before their breath meter runs out, especially if combat is initiated, or they will begin to take large chunks of health damage every second, and eventually drown.

While it is imperative that a player recover his breath, it can be a viable PvP tactic to stun or root players in place while underwater and allow them to drown.

Water breathing
Though the breath meter lasts three minutes by default, there are many ways to delay or prevent drowning:

Objects

 * In some areas where a quest requires going under for long periods, such as by Shadowprey Village in Desolace, or where the water is very deep, such as Glimmer Bay in Borean Tundra, there may be Bubbly Fissures, a cracked mound on the seafloor with a stream of air bubbles rising from it. Placing yourself just above the fissure will replenish your breath.
 * In Vashj'ir, there are giant clams that provide air; this can be useful for players during their intro quest to receive their permanent zone breathing buff.
 * Offshore of the Broken Shore in the Broken Isles, Vaporous Abalones can be found on the seafloor.

Racial abilities

 * The Forsaken, being an undead race, have no need to breathe. Originally their racial was being able to hold their breath for up to 10 minutes (Underwater Breathing).  For some time this was removed, then given back, and then "upgraded" to Touch of the Grave in Patch 6.0.2. See Forsaken Racial Traits.

Class abilities

 * Druids will shapeshift into an aquatic creature in water while in Travel Form (Level 18), allowing them limitless water breathing. It also grants them +50% swim speed.
 * The original version was a separate Aquatic Form.
 * Unending Breath grants underwater breathing for 10 minutes and +20% swim speed (level 16 Warlock spell, can be cast on others).

Items
Up to Wrath of the Lich King, quests going under for long periods usually gave items for players to use, but the later expansions from Cataclysm and onward avoided this by giving a quest in their storyline to provide a permanent area buff instead (likely to help avoid bag clutter).


 * Elixir of Water Breathing allows underwater breathing for 30 minutes (requires Level 8, crafted by Alchemists), was also a quest reward from Gyromast's Revenge.
 * Elixir of Greater Water Breathing allows underwater breathing for 1 hour (requires Level 35, crafted by Alchemists).
 * Deepdive Helmet allows unlimited underwater breathing (crafted by Engineering skill 230).
 * Hydrocane from Viscous Fallout in Gnomeregan.
 * Hook of the Master Angler won from the Stranglethorn Fishing Extravaganza in Booty Bay can turn the player into a fish.
 * Noggenfogger Elixir bought from Marin Noggenfogger's wife Sprinkle in Gadgetzan (originally introduced in Noggenfogger Elixir (quest)) has a good chance to turn you into a skeleton with underwater breathing for 10 minutes.
 * Potion of Water Breathing is provided from a few quests in Zangarmarsh and can be kept afterward. It has three charges of underwater breathing for one hour each.
 * Nagrand Cherry, which comes in one stack of 20, grants underwater breathing for 5 minutes per cherry, from A Rare Bean (quest) in Nagrand.
 * Tua'kea's Breathing Bladder, given for the quest Tua'kea's Crab Traps can be kept afterward. It has six charges of underwater breathing for 10 minutes each.
 * Mastercraft Kalu'ak Fishing Pole, available after becoming with The Kalu'ak.
 * Cursed Swabby Helmet, a toy from the Sunken Treasure on the Timeless Isle. Lasts for 15 minutes on a one-hour cooldown and only usable in Pandaria.
 * The artifact fishing pole Underlight Angler, with the trait Underlight Blessing purchased at rank seven (at the earliest). This essentially combines the Hook of the Master Angler with the Mastercraft Kalu'ak Fishing Pole. (NOTE: Cannot be active while in combat!)
 * Shimmerscale Diving Helmet provides a single charge of underwater breathing for 15 minutes. Crafted by BfA leatherworkers. (Can be paired with Shimmerscale Diving Suit.)
 * Pocket-Sized Computation Device, using an inserted Supplemental Oxygenation Device blue punchcard increases the three minutes to 33 minutes.

Removed

 * Band of Icy Depths from the Scepter of the Shifting Sands quest The Wrath of Neptulon.