Shortly after the release of the game, web forums and the Youtube were flooded with numerous claims of the Megalodon, leading players to investigate this myth. Washington Beach, Ocean Beach, Vice City River and the Leaf Links are the locations, where players claim to have witnessed such a shark. A rational explanation leads us to the fact that these sightings are the cause of different observing locus, misleading players to the thought of the Megalodon.
Many of the reports include a shark attack, resulting in death. These shark attacks are disclosed in the GTA Vice City Manual: Shark attacks off Vice City happen a few times a year and there are more sharks out there than you would like to think - Best advise: Stay out of the water!. It is more likely an explanation from Rockstar to explain the fact that the player can't swim, but several players hold the belief this statement is based on the Megalodon. Another feature concerning these attacks is, that if the player knocks pedestrians off the bridge into the water, near the Lighthouse, many sharks spawn near them. This could be possible reference to these shark attacks.
Several videos featuring the Megalodon Shark became viral, which later turned out to be modified. This myth still remains in limbo, despite numerous efforts over the years. One of the videos is featured below:
New Video Investigation
The following video features the Giant Shark spotted under the Vice River Quay. This video can't be ruled out. It is neither fake nor officially authentic. It's a random video on the web, leaving thousands of questions unanswered, abandoning its status in limbo, but the editing of the video leaves the authenticity of the video in question.