Water

Water is a common feature in the GTA series that serves as a natural barrier for the world, break up landmasses, and give a more realistic effect on the game in both appearance and ambient sounds. After GTA III, Rockstar decided they did not like having inaccessible landmasses visible, so in-game worlds surrounded by infinite oceans on all sides even if lore dictates the world is land-locked - by implementing large bodies of water, the boundaries of the in-game world can be effectively hidden.

2D Universe
In the 2D Universe, water is limited in interaction. In GTA 1 it is possible to walk into water on their level and paddle for a handful of seconds before drowning. If the player falls into the water from a height, or tries to sail a boat, they will instantly drown however. If the player falls into water at all in GTA 2, they will instantly die.

Grand Theft Auto III
The first game of the 3D Universe, GTA III's water is opaque, polluted and toxic. If the player completely submerges himself inside water by walking or driving into it, the player's health will begin to decrease rapidly, and his body will slowly float to the surface. The in-game explanation for this is that an oil spill had coated the city's harbor in a thick hazardous film, a direct result of deregulation of the harbor. Fish are seen in Gone Fishing, but are never seen before or after.

Grand Theft Auto: Vice City
In GTA Vice City more boats are available to drive, although the player will still die if fully submerged in sea water, the result of rip tides in the ocean currents. Compared to GTA III, the water is transparent and featured sea floors (although "deep water" still had no bottom), sunken wrecks, fish, sharks, and dolphins, although they are not solid and do not respond to interaction.

Grand Theft Auto: San Andreas
In GTA San Andreas the player is for the first time able to swim in the water and even dive and swim underwater, as well as drive a large variety of boats. When underneath the water, CJ will slowly lose oxygen and eventually die if he stayed under water for too long. The water in GTA San Andreas is mostly transparent and has a better overall look than the water in GTA Vice City. There are many sea creatures in this game such as jellyfish and dolphins, although animals are still not solid and do not interact with the player.

Grand Theft Auto Advance
In GTA Advance, water is not accessible by foot no more than the shore as invisible barriers surround all pools of water in the game. However, the player can freely drive any vehicle into water, though it will quickly sink. If the players vehicle is between land and water, splash effects will be seen as a warning that going any further in will sink the vehicle and lead to a fatal result.

Grand Theft Auto: Liberty City Stories
In GTA Liberty City Stories, as in the games before San Andreas, the player can't swim, though they can drive some boats. The water is deep blue-colored and non-transparent, but not as polluted as it was in GTA III.

Grand Theft Auto: Vice City Stories
In GTA Vice City Stories, after many complaints because swimming was impossible in the previous game (GTA Liberty City Stories), Rockstar made swimming possible again, albeit without the diving function. It only permits swimming for a limited amount of time, determined by a stamina bar which decreases as the player remains in the water. When the bar runs out, the player's health decreases, as the player will drown to death. Completing the Beach Patrol side mission, however, will stop the player's stamina from depleting. The water is turquoise and slightly transparent.

Grand Theft Auto IV + Episodes from Liberty City
The water in GTA IV and the EFLC is partially transparent and highly reflective. The player can not go underwater, being restricted to swimming on the surface of the water, non-player characters can also swim for a short period of time. The only actual advantage of water in the HD Universe is that it creates a quicker route between islands if the player finds a boat. Although Liberty City is described as land-locked to the North and West, it is surrounded by water in-game.

Grand Theft Auto: Chinatown Wars
In GTA Chinatown Wars, like in the previous HD Universe games, the player can only swim on the surface. The boats are similar as well, except for the Wet Ski. There are no fish. The water looks rather transparent, so some radioactive waste, as well as some underwater dunes and four "Here Be Dragons!" Easter Egg messages (one in the north-east, one in the north-west, one in the south-east and one in the south-west) can be found.

Grand Theft Auto V
In GTA V, swimming returns with major upgrades. Just like in GTA San Andreas, the player can swim in and under water, albeit with some changes. To swim underwater, the player can use a scuba suit or drive a submarine. Underwater is much more detailed, and for the first time, there are sharks that can be interacted with. There are multiple vehicles the player may use to traverse the waters with. There are shipwrecks, hidden underwater that have hidden treasures inside, that the player can retrieve for money. Weapons, health, and armor can also be found underwater. A dead whale's skeleton and a crashed UFO can also be found in specific locations underwater. Another new feature into GTA V is if the player dives too deep, the submarine will be destroyed by the water pressure, killing them. Like Liberty City, San Andreas is described as land-locked to the North and East, with the ocean only serving as a gameplay barrier.

Glitch

 * A glitch in GTA: Vice City Stories involves walking on the water, Get on top of an Airtrain and try not to fall behind. When it leaves the airport, after a while Vic will be ejected and land on the water below, being able to run, walk and shoot on the water. Using a rocket launcher or jumping, however, will erase the glitch and start swimming again.

Trivia

 * In most 3D Universe games (Grand Theft Auto III, Grand Theft Auto Vice City, Grand Theft Auto Advance and Grand Theft Auto: Liberty City Stories), the water bodies serve as a mean to retain the players from a locked island, while the bridge that connects the locked island and the rest of the map is closed. However, with the advent of GTA San Andreas, players are able to swim between the islands without dying, incurring the huge attention of the game's law enforcement agencies.
 * In Grand Theft Auto: Vice City getting into shallow bodies of water outside of the ocean (pools and ponds) will not kill the player even if he crouches so that his head is submerged.
 * In Grand Theft Auto: Vice City Stories when swimming has been limited, the river waves serve as a mean to retain the player from swimming across to locked island while the bridges that connects the locked island and the rest of the map are closed.
 * In Grand Theft Auto: San Andreas and Grand Theft Auto IV, the rivers are a means to reach locked islands, while awarding immediate, extreme (a 4 star wanted level in GTA SA and a 6 star wanted level in GTA IV) attention from the game's law enforcement agencies.
 * In Grand Theft Auto: Chinatown Wars, The Lost and Damned, The Ballad of Gay Tony, and Grand Theft Auto V, the map is unlocked from the beginning, so the player can swim freely around the city. It should however be noted, that in GTA V, the entire map is surrounded by water, instead of the traditional "islands" that would be unlocked throughout the storyline, therefore making the procedure of locking parts of the map until a later date irrelevant.
 * In GTA V, it is possible to take damage from falling in the water from great heights, sometimes dying instantly from larger falls. This is realistic, as once at terminal velocity, the effect of striking water would be the same as hitting concrete at 70 miles per hour.
 * In GTA IV (also Episodes) and GTA V, If the player submerges a car in water that is shallow enough to still see it, they will notice that the badging is missing, and the Headlights/Taillights are broken, even if they were not broken before. But once the vehicle is back on the surface, the headlights/taillights and badging will now re-appear (the car must be underwater and the player on the surface or standing up for this to work).