Teacher Leesa Espley became part of the crew at Hunstanton RNLI in Norfolk in 2003.
One of the charity's first hovercraft arrived at the station shortly afterwards.
And Leesa, now 52, went on to become the RNLI's first female hovercraft pilot - a duty she still performs today at the controls of the
Hunstanton Flyer, along with crewing the station's inshore lifeboat Spirit of West Norfolk.
Before she could fly the hover, she paid privately for eye surgery to correct her short sight.
'I always knew I was going to be in it for the long haul,' she said. 'You're doing something for your community, you're doing something that's really worthwhile.
'And the people at the station are great, there's just so much camaraderie.
'You're working as a team, with like-minded people and I just love doing what we do.
'Being part of it gives you a real sense of achievement and the crew is like an extension of your family.'
Back on dry land, Leesa has also ran two London Marathons and a Great North Run to raise funds for the RNLI, whose lifesaving work is only made possible by the generosity of its supporters.
And back in 2012, she crewed one of the safety boats for the sailing at Weymouth in Dorset, when the Olympics came to England.
'It was amazing,' she said. 'I'd never have had that opportunity if I hadn't been part of the RNLI.'
Hunstanton RNLI Lifeboat Operations Manager, Rigil Kent said: 'We've got a number of firsts at the station but 20 years' commitment is a big thing.
'Although we have got some long-serving crew, the average is 10 years, so for someone to do 20 or more is pretty special.'
Notes for editor
Hunstanton, which celebrates its 200th anniversary this year, is one of the RNLI's busiest stations in Norfolk.
The station is one of just four around the coastline of the UK and Ireland which operates a hovercraft.
Since Hunstanton's current station opened in 1979, its inshore lifeboat Spirit of West Norfolk and her predecessors have helped save 140 lives and render assistance to more than 600 people who found themselves in difficulty or in danger.
In 2003, she was joined by the hovercraft Hunstanton Flyer, which has since then been launched 250 times, saved 13 lives and assisted a further 150 people.
RNLI media contacts
For more information call Chris Bishop, Hunstanton RNLI volunteer Deputy Lifeboat Press Officer on 07584 147219 or Clare Hopps, RNLI Regional Communications Manager (North East and East) on: 07824 518641.
Key facts about the RNLI
The RNLI is the charity that saves lives at sea. Its volunteers provide a 24-hour search and rescue service around the United Kingdom and Republic of Ireland coasts. The RNLI operates 238 lifeboat stations in the UK and Ireland and more than 240 lifeguard units on beaches around the UK and Channel Islands. The RNLI is independent of Coastguard and government and depends on voluntary donations and legacies to maintain its rescue service. Since the RNLI was founded in 1824, its lifeboat crews and lifeguards have saved over 146,700 lives.
