A Norfolk man has written a heartfelt letter to the lifeboat crew who saved his life 50 years ago to tell them: "I owe you everything."

Martin Stephen, then aged 21, almost died when he jumped into the sea to try and rescue his cousin David Jeffrey, 11, who had been swept off the rocks at the entrance to Dunbar harbour on December 23, 1970.

Mr Stephen was unconscious and sinking beneath the waves when Dunbar RNLI lifeboat crewmen David Brunton and Jonathan Alston jumped into the water to grab him.

The rest of the crew then hauled the three men back on board and managed to get Mr Stephen breathing through mouth-to-mouth resuscitation.

The lifeboat searched for David's body but he could not be found.

Eastern Daily Press: Undated handout photo issued by the RNLI of the six Brunton brothers who all served on the crew of the Dunbar RNLI (left to right) Bob Marr, the brothers' uncle, Robert George Brunton, David Brunton, Peter Brunton, William Brunton, Jimmy Brunton and Ralph Brunton.Undated handout photo issued by the RNLI of the six Brunton brothers who all served on the crew of the Dunbar RNLI (left to right) Bob Marr, the brothers' uncle, Robert George Brunton, David Brunton, Peter Brunton, William Brunton, Jimmy Brunton and Ralph Brunton. (Image: Dunbar RNLI/PA Wire)

Mr Brunton was awarded the RNLI Bronze Medal for Gallantry and Mr Alston received the institution's Thanks on Vellum for the rescue.

As the 50th anniversary of the rescue approached, Mr Stephen, now 71 and a retired headteacher and writer living in Norfolk, wrote to current Dunbar lifeboat coxswain Gary Fairbairn to thank the crew.

Mr Stephen, wrote: "I've had 50 years of the happiest possible marriage, three sons and five grandchildren.

"All in all I've been able to live a wonderful life, but only because of the bravery of one man, the skill of another and the dedication and courage of the crew of the Dunbar lifeboat.

"I owe you everything."

Eastern Daily Press: Undated handout photo issued by the RNLI of the lifeboat crew from the Dunbar RNLI in 1966 (left to right) Charlie Smith, 'Fuzz' Davies, 'Teedie' Lees, Jonathan 'Jonah' Alston, Alexander 'Zander' Wilson, Coxswain Robert George Brunton and mechanic Bill Windram.Undated handout photo issued by the RNLI of the lifeboat crew from the Dunbar RNLI in 1966 (left to right) Charlie Smith, 'Fuzz' Davies, 'Teedie' Lees, Jonathan 'Jonah' Alston, Alexander 'Zander' Wilson, Coxswain Robert George Brunton and mechanic Bill Windram. (Image: Dunbar RNLI/PA Wire)

The 1970 tragedy occurred while Mr Stephen and his family were in Dunbar, East Lothian to spend Christmas with his aunt Maeve Jeffrey.

On the night of December 23, he and his cousins David and Angus, 14, went to watch waves as high as 10 metres crash over the harbour wall.

Mr Stephen said: "We were standing at the mouth of the harbour when a freak wave came over, caught Davie and smashed him against the rocks, knocking him into the water.

"I hadn't even realised he had been standing higher up on the rocks. As soon as I saw him I jumped in and managed to reach him. I held him in the rescue position but we kept going under. I think he was already dead.

"We were in about a 10ft swell and kept going under. We were in the water for about 10 minutes."