Water can be found in many maps as a terrain feature and gameplay element. There are two types of water: shallow and deep. Shallow water will absorb all impact from a fall, and reveal the footsteps of Spies (which will also be more audible). It is otherwise a cosmetic part of the game.
Deep water allows a character to fully submerge and swim around. Immersion in deep water will instantly negate the effects of afterburn, Jarate, Mad Milk, and the Gas Passer, and will prevent these debuffs from occurring until the player surfaces. Some maps feature submerged routes into the enemy base, which are often poorly defended in comparison to ground-level entrances. Like shallow water, deep water also negates fall damage.
Engineers can construct buildings underwater just like on land. Due to the low visibility of submerged objects, deep water is often a great spot to conceal a Teleporter or a Sentry Gun. However, Sentry Guns cannot see targets that are across the water's boundary no matter how close they are, making submerged Sentry Guns solely useful for underwater targets.
Remaining submerged in water for too long will cause the player to drown. While drowning, a gagging, choking sound is heard and the player will experience a periodic loss of health and will flinch (such as with bleeding and afterburn effects), and the screen will flash blue to warn the player. To negate this, the player must reach the surface, where the health lost due to drowning regenerates over time at a gradually increased rate. Upon surfacing from the water after drowning, a gurgling sound is heard by the player. Standing next to a Dispenser, picking up a Medkit, or being healed by a Medic will restore the player's health faster than it is lost due to drowning.
Deep water has several impairments:
- Submerging in water will obscure the player's vision with bubbles for a few seconds.
- Surfacing on the water can affect vision, making aiming difficult. To counter this, fully submerge, especially if battling a submerged opponent.
- Swimming in deep water will decrease the maneuverability of all classes by 20%, making them vulnerable targets for enemies who have the advantage of higher ground or more suitable weapons.
- Players are considered to be in a constant state of falling while in water, and are not considered standing still even when resting on the bottom of the body of water. As a result:
- Players cannot taunt while underwater, or consume any lunchbox items. (Such items can still be dropped if possible.)
- Players cannot enter teleporters, although they can still emerge from teleporter exits per normal.
- The Scout cannot double jump while underwater.
- The Cloak and Dagger cannot recharge while cloaked underwater.
- All in-game sound is muffled while the player is underwater, including voice chat. Setting the cvar
dsp_waterto 0 removes this effect.
- Projectiles that must be thrown by hand (Sandman baseballs, Wrap Assassin festive ornaments, Mad Milk, Jarate) cannot be used.
- Firing any of the Pyro's flamethrowers underwater will simply waste ammo and eject a stream of harmless bubbles instead of fire; Pyros are also unable to airblast at all. Additionally, flare-based secondary weapons cannot be fired. The Sharpened Volcano Fragment will not ignite enemies underwater.
- The Demoman's projectiles will travel slower and cover a shorter distance underwater due to the physical effects of the water on them.
- The Engineer cannot fire his Short Circuit underwater.
- Shots fired by the Medic's Crusader's Crossbow or the Sniper's Huntsman and Fortified Compound will be deflected significantly when fired into water.
- Any player surfacing from a body of water will display dripping water particles for a few seconds. This is detrimental to cloaked Spies, as this can reveal his presence to the enemy. Likewise, if a Spy attempts to Cloak while underwater, the bubbles they make can still be seen, although they are still difficult to catch. Players who are dripping with water are considered "wet", and the Neon Annihilator will do critical damage against them even if they are on dry land.
Maps with water
- 2Fort: There is a large pool of deep water beneath the bridge in the center of the map. The Sewers at each team's base contain shallow water as well.
- 2Fort_Invasion: Large pool of deep water beneath the bridge in the center of the map. From the main map.
- Asteroid: On each side, inside both base there deep water under the B point.
- Badlands (Arena) and Badlands (King of the Hill): On each side, there is a small pond of deep water beneath the small concrete bridge to the left of the spawn room.
- Bigrock: A large pool of water is seen near the robot spawn area, with a waterfall running into it.
- Doomsday: There is a small pool of deep water at the broken crate area, underneath the pick-up location for the neutral Australium.
- Double Cross: A pool of deep water is found beneath the drop hatches of the spawn rooms.
- Eyeaduct: A large body of water containing Loot Island, separate from the main map.
- Freight: Two large bodies of water connect from the exits of RED and BLU's buildings under the main buildings to a small pool on the other side of the midpoint, allowing for flanking and an easy way around the trains.
- Frontier: The rightmost exit of BLU spawn leads to a small, barely noticeable area covered with shallow water.
- Ghost Fort: A large body of water containing Skull Island, separate from the main map.
- Hydro: There is shallow water in the Dam and Warehouse territories.
- Lakeside: In the center building next to the control point there is a small pool of deep water.
- Mannhattan: A large ocean exists that surrounds the outer areas of the robot carrier tank.
- Moonshine Event:Lake surrounds the center control point areas.
- Nightfall (stage 3 only): There is a very small pond of deep water in the center of the map, under the cart tracks.
- Pipeline (stage 3 only): The small canal beneath the cart tracks has deep water.
- Powerhouse: The center of the map has a channel of deep water.
- Ravine: At the lower side of the map underneath the tall large building, deep water can be found in the small alcove.
- Rottenburg: At the left side of the spawn area, a large river of water can be found over a railing.
- Sawmill (all variations): Large bodies of deep water are found at the Lumbershack and Waterfall areas of the map. In the Capture the Flag version, shallow water also covers the Intelligence room's floor.
- Standin: Shallow water surrounds the platform Point A is on.
- Snowycoast: Water surrounds the mothership at the final point.
- Sunshine: Ocean outside the map.
- Swiftwater: First BLU spawn lead to small river.
- Suijin: There river surrounds the center koth point with waterfalls and under the cliff.
- Thunder Mountain (stage 2 only): Right outside the BLU spawn there's a small stream which has deep water.
- Timberlodge : Small pools around the map.
- Watchtower: There are small ponds of deep water around the valley below the central tower.
- Well (all variations): Deep water channels outside the team's buildings consisting of underwater routes connecting each team's base building to the central train house building. The Capture the Flag version is similar to the Control Point version, except the route to the central building is removed with the building itself. The Arena version features a small pool adjacent to the central building which offers a quick route to the central point.
- Watergate: The center of the map has a channel of deep water.
| Escape the Heat|
Jump into a pool of refreshing water while on fire.
| The Cycle|
In a single life, kill an enemy while you are on the ground, in the air, and in the water.
| Krazy Ivan|
Kill 50 enemies while both you and your victim are underwater.
| Wet Work|
Kill five enemies while they are in the water.
- Fixed rare crash when players exited water.
- Added a particle effect for when a player enters the water.
- Updated ripple effects for water drips to improve performance.
- Fixed the DX8 water effect.