Water is a common feature in the GTA series to give a more realistic effect on the game in both appearance and ambient sounds. Water surrounds the map to create land for the map. The other common feature shown throughout the series is trees.
By the first game of the 3D Universe, GTA III, the player could find boats to sail. However, if the player drove in to, walked in to or fell in to water they would drown to death. Although, at some parts of the game Claude can be completely submerged in water and not lose health (places like Portland Beach and on the Belleville Park on the lake or in some small water places with no fish but with green lilies on there in Staunton Island ). The water in the game was mostly a non transparent blue color and no fish could be found swimming in it.
GTA Vice City
In GTA Vice City more boats were available to drive in although the player would still die if fully submerged in water. The water was more transparant and overall looked much better than in GTA III and was even home to several different types of sea creatures like sharks and dolphins although they were transparant and not solid, they would not interact with the player. The same as in GTA III, the player can walk over low-emerged water in lakes over the city.
GTA San Andreas
In GTA San Andreas the player was for the first time able to swim in the water and even swim underneath the water, as well as drive several different variety of boats. When underneath the water, CJ would lose oxygen and eventually die if he stayed under water for too long. Strangely the water looked a bit less sparkly and transparant than Vice City's. There were also more sea creatures this time such as Jellyfish and dolphins, however there were no sharks, although many people claim to have seen them, sparking a popular myth.
In GTA IV there are a few boats, good looking water and no sea creatures and Niko 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. There is an extremely rare glitch where sometimes the rivers and the ocean levels will rise on the coast. A surface of water will float above the street and the levels change again when the weather cheat is continuously activated. Despite the glitch, the game acts like it's on land unless the player enters the actual water outside the coastline. This glitch is so rare that the cause is unknown, but it is probably linked to a bug in the weather cheat. Also, if you drive a vehicle into the water, the entire car will short out. There is also another bug in which when the car's rear or front end is submerged to it's tailights/headlights, the breakable "plastic" covering the inner light will become invisible when seen through the water.
In GTA V, swimming returns, but even better. Just like GTA San Andreas, the player can swim in and under water but they've made it a little better. To swim underwater, the player must use a scuba suit or sail a submarine. Underwater will be much more detailed too and for the first time, there will be sharks. There will also be boats, presumably Skimmer planes, that will be able to land and take off on water. Cars will most definitely sink as well, causing anyone trapped inside to die. There will also be shipwrecks hidden underwater that have hidden treasure inside them.