This is a very common question and there is no way to drive a car on water in the standard GTA III game. There are, however ways of manouvering on the water using one of the four types of boats that exists in the game.
water for all car
Yes you can drive cars in the game on water.You need to type the cheat for floating cars on water.
aws
There is no cheat for jet plane in GTA Vice City.you can get it in GTA sanandreas but not in vice city.
driftking
comeflywithme is the cheat to get a flying car.You can fly for short distance in the car using cheat.
sorry there is no turismo cheat on san Andreas
Car 555 time
all you need to do is drive your car into an empty safe house garage and get back in it! good as new!
Yes,the sea ways cheat work in gta vice city.The sea ways cheat is for driving car on the water.
plaNE helicopter flying car cheat