The crocodile was first spotted by people on a speedboat who had stopped to fish some 200 metres off Bang Tao Beach.
Local officials were notified, who launched a drone to confirm the sighting, The Phuket News was told.
Local officials confirmed that it was a crocodile heading towards Surin Beach.
The sighting was reported to Manoch Punchalad, the newly elected Chief of Cherng Talay Tambon Administrative Organization (OrBorTor), who in turn reported the sighting to Phuket Governor Narong Woonciew, The Phuket News was told.
Governor Narong is aware of the incident and has urged tourists on beaches in the area to be careful and to remain vigilant for any danger.
So far The Phuket News has not been informed of any other action taken by officials.