HMS Severn snared three fishermen flouting international laws during two weeks of hectic patrols in European waters.

The arrests of Belgian and Dutch trawlers and a British scalloper came on the eve of more good news for the Fishery Protection Squadron: the trio which form the backbone of the squadron, Severn, Mersey and Tyne will serve for another five years.

The ships are leased from the VT Group on a five-year deal which is due to expire in 2008.

Whitehall has agreed to extend the lease until 2013 in a £52m deal clinched with the Portsmouth shipbuilders.

Severn is the middle sister of the trio. In a combined operation with the Dutch coastguard monitoring suspected illegal activity in the North Sea, the ship’s boarding team joined the Netherlands’ patrol vessel Barend Biesheuvel as they trailed a Belgian trawler.

The boarders pounced on the Mooie Meid in particularly foul conditions, clambering over the Belgian trawler’s side much to the fishermen’s surprise.

The boarding party, led by Severn’s 1st Lieutenant Lt Jim Lovell, immediately found the Mooie Meid was using illegal nets – blatantly using ‘blinders’ which increase haul amounts by targeting under-size fish.

Chatting with the crew, the boarders found that the ship was working on behalf of the Belgian Fisheries Scientific Institute – who were horrified to learn that the skipper was using illegal nets to gather data, rendering it invalid.

“The skipper said that he believed he was safe using his illegal nets as it was too rough for boarding operations,” said Lt Cdr Rex Cox, Severn’s Commanding Officer.

“He’d underestimated the determination of the RN and Dutch coastguard.”

The vessel was detained in Lowestoft where magistrates fined the skipper £10,000 and confiscated much of his gear, costing him in total around £45,000.

Despite gale force winds in the North Sea, Severn headed back out to sea the same day, hiding in the shelter of gas and oil rigs before stealthily pouncing on a Dutch boat, Cornelius Senior, which was under-reporting her catch.

She too was detained in Lowestoft, where officials from the Marine Fisheries Agency issued the skipper with two written warnings.

Heading back to Portsmouth for some well-deserved leave, the ship carried out the final boarding of 2006 by the entire Fishery Protection Squadron.

This time it was the Western Belle which fell foul of Severn’s diligence. She was detained in Shoreham after a significant quantity of under-sized scallops were discovered on board.

“It was a challenging patrol to end the year. My ship’s company put in a magnificent performance in some atrocious weather. The results speak for themselves,” Lt Cdr Cox added.