According to the deputy director of Nopparattanathara Beach and Phi Phi Island National Park, Boonnam Choiradum, the longtail was carrying 20 passengers and two crew on a boat with a limit of 13 passengers.
According to the regional director of the Phuket-based Marine 5 Office, Vichai Khumkhong, the longtail was carrying the right number of passengers.
Both agreed, however, that some of the passengers - by the higher estimate totalling 20, including four children - were not fitted out with lifejackets. The operators will face prosecution as a result.
Park rangers spotted the longtail off Ao Nang - 500 metres off the beach according to one authority, 200 metres according to the other - about 10.30am yesterday in rolling seas.
The rangers could see people waving through binoculars and the passengers were relieved to be rescued.
Difficulties were encountered as the vessel made a day trip to four destinations off Krabi - Khoa Pad, Talay Wake, Khao Pai and Railay beach.
Investigations are continuing. Phuketwan would welcome contact from anyone who was on the longtail at the time.