The Ghost Vortex is a proven myth in Grand Theft Auto: San Andreas that involves Vortex, a hovercraft that spawns in Bayside Marina. A similar effect can be reproduced statewide as a glitch.
Description[]
In Bayside Marina, a Vortex spawns on the beach. As soon as it spawns, it can be observed sliding down the hill and into the water, seemingly as if it is driving by itself. The Vortex then sinks and creates a somewhat large splash on the surface of the water. Players who see this may believe that the Vortex drove by itself. This is, however, a glitch, and it is highly unlikely that game developers implemented this on purpose.
This myth is the result of a glitch, and it is very much similar to the same glitch that causes the Ghost Cars to roll down the hills. The Vortex spawns on an incline, and due to the game's gravity, it slides down the hill and into the water when it spawns. The player can also spawn a Vortex on the hill and cause it to slide down the hill, but it has to be spawned at a certain angle though and it must be facing forwards.
The Vortex sometimes doesn't sink immediately, meaning the player can get into it. However, if the player crashes into one of the cliffs beside the bay, the Vortex will sink.
Another thing that can happen is that the Vortex can explode upon spawning. The strange thing about it is that although it is destroyed, the white vapor from beneath it continues to appear. This is likely a minor visual glitch.
Many players have reported that the Vortex chases the player. This has been proven to be a glitch and can be seen statewide. If the player spawns a Vortex in any body of water and blows it up using a Heat-Seeking Rocket Launcher the vortex will start gliding along the water as if a ghost is driving it and many players have reported that the Vortex even glides towards CJ and other pedestrians. Players have also reported seeing the Vortex spinning in circles after blowing up.