A former Sheppey lifeboat which saved the crew of pirate station Radio Caroline is up for sale.

The all-weather Helen Turnbull originally cost £100,000 and was stationed at Sheerness from 1974 to 1996, during which time it was launched 649 times and saved 297 lives.

Among those were the four-man crew of Radio Caroline when their ship the Mi Amigo ran aground on a sandbank on March 19, 1980.

The Helen Turnbull later served in Ireland between 1996 and 1998 before being retired by the RNLI. It was sold off in 1999.

The Waveney-class lifeboat has since been converted into a six-berth pleasure boat with an additional cabin, galley with fridge and twin Caterpillar 3208T marine diesel engines.

It has been based at Douglas on the Isle of Man and has its own eight-man life raft and 12 life jackets. The price has not been released.

It was the RNLI’s third lifeboat for Sheerness and replaced the Gertrude on April 4, 1974. It was itself replaced by the current Trent-class George and Ivy Swanson in March 1996.

Commenting online, Michael Butler, from Ontario, Canada, wrote: “I was christened on this boat in 1995 when it was lifeboat 44-009 at Sheerness.”

The boat, now called Badger, is being sold by Irish company Nelson’s Boats, from County Down.

Its most famous launch was at 6.15pm on March 19, 1980, when the crew received the call to go to the Mi Amigo.

Heavy winds had whipped up the waves in the North Sea and snapped the anchor of Radio Caroline’s ship the Mi Amigo at 1.30pm. The four-man crew, including British DJs Stevie Gordon and Tom Anderson, deployed the emergency anchor but the ship still ran aground on Long Sand sandbank. At midnight the two DJs announced on air they were abandoning ship.

The Helen Turnbull had been moored a mile from the radio ship, waiting for the tide to rise, as Force 9 easterly gales pounded the broadcaster. For two hours the lifeboat crew had tried to persuade the four men on board to leave.

At 9.30pm the ship began to take in water. Finally, the pirates agreed to abandon ship.

They did so in such a rush they left behind all their personal belongings and the station’s master tapes.

It took the lifeboat crew nearly an hour, battling mountainous seas and risking their own lives, to rescue the pirates, including Wilson II, the ship’s canary.

The Mi Amigo’s generator was left on to provide power for navigation lights, but as the crew headed for safety they watched as the ship’s lights flickered and went out.

Three hours later the pirates landed at Sheerness and were interviewed by police. None were prosecuted.