In this cool video I gonna show you how to be able to swim on land.
At first you have to drive to Los Santos Customs near the airport.
Park your car at the marked location in front of the wall, climb onto the roof of the car and then
jump and try to climb the wall of the building. Now you fall into water and then you are able to
swim to the near located beach where you can swim in the mid air.
More details how to swimming in mid air in the video below: