A Vietnamese vessel illegally fishing in Thai waters was caught by the Thai Navy after a high-speed chase.

The one-tonne boat was reportedly dredging sea cucumbers some 50 miles off the coast of Songkhla province, on January 13.

Local anglers reported to the 2nd Area Naval Command after spotting the foreign vessel lurking in the area.

The Royal Thai Navy's HTMS Pattani and a patrol aircraft were deployed to the scene and, upon finding the Vietnamese fishermen, chased them across the Gulf of Thailand.

Dramatic footage shows the navy ship catching up to the smaller wooden boat, seen carving up water as it tried to escape.

The HTMS Pattani was later able to block its path, and the five Vietnamese crewmen were arrested. Two barrels of sea cucumbers were also found onboard.

Vice Admiral Res Wongtrakul, Commander of the 2nd Area Naval Command, said the fishermen were charged for allegedly violating the Fisheries Act, the Act on Fishing Rights in Thai Fisheries, and the Immigration Act.

They were taken to the Songkhla Naval Base Pier for further proceedings.

The navy officer said: 'This operation is in line with the 2025 policy of the Commander of the Royal Thai Navy, which focuses on protecting our national interests at sea, preventing and resolving maritime threats, and assisting the public, especially with the encroachment of Thai waters by foreign fishing boats that illegally fish. This operation resulted in a successful arrest.

'We would like to thank the fishermen for their cooperation in reporting information about the boat that committed the offenses.'

Authorities said it was the second boat caught illegally fishing in Thai territory this year.

The Thai Navy said it has arrested 15 foreign fishing boats and 75 fishermen or boat operators since 2024.