The operation was carried out following tip-offs by Thai fishing boat owners that dozens of Vietnamese boats were fishing in Thai waters without permission.
The crewmembers were brought to the Songkhla Naval Base in the morning and were provided food and water pending interrogation. The six boats were expected to arrive at the base later in the evening.
Earlier, on September 5, the Second Naval Area Command arrested three Vietnamese boats with 17 crew members onboard while they were fishing in Thai waters.