Fisherman, villagers and staff at the Mai Khao Dream hotel first spotted the roaming croc around 8.30am, and alerted local authorities.
The croc is believed to be around 3 metres in length, and it is proving a bit a problem for authorities and the local Kusoldharm to catch because it keeps disappearing.
At the moment, locals are at the beach warning people not to swim, and Phuket Governor Maitree Intusut is on his way to the area to try and work out what to do with the animal.
Yesterday, locals took a boat out to see the giant croc. But when they got close, it disappeared and they spent about three hours circling around looking for it, before abandoning their mission.