The Phuket Marine Office was informed of the fire, on the ‘Flamingo Lady 2’ tour catamaran, at about 10:35am
The boat was transiting between Koh Naka Yai and Koh Raet when the fire broke out, reported staff at Ao Po Pier.
According to the boat’s captain, Charoon Rungsamut, 31, the vessel departed from Ao Po Pier at 10am with 22 tourists aboard, bound for Koh Naka Yai.
After safely dropping off the passengers, the boat began its return trip with only Mr Charoon and the boat’s machine operator, Kritsada Karnriab, 23, onboard.
During the return journey, the right engine of the Flamingo Lady 2 malfunctioned, causing it to overheat. Sparks from the engine ignited oil vapours, leading to a fire, he said.
Despite efforts by both the captain and mechanic to address the issue, the fire quickly spread.
Mr Charoon sustained minor injuries to his leg while attempting to contain the fire and was transported to Thalang Hospital for treatment.
No passengers were aboard at the time of the incident.
Authorities are investigating the cause of the fire and assessing the extent of the damage.
The vessel, made of aluminium, is registered under the number 625100075 and has a valid boat licence until April 2025, officials confirmed.