"I thought I was going to drown and I have been scared of water ever since. The classes have helped pull me out of that."
Frankie Barnett is 75 years old and, until three months ago, she had never been in a swimming pool.
She had always avoided swimming after she developed a fear of water caused by a traumatic incident during her childhood.
"My twin sister and a friend pushed me under the water and sat on me when I was quite young.
"I was so nervous when we first got in but my fear of water is completely gone. My next challenge is swimming in the sea."
Frankie pushed herself to learn to swim after her grandchildren started to get lessons.
"Kids today are such good swimmers," she said.
"I wanted to go to the pool with my grandchildren. I'm really proud of myself to have done this."
Frankie is part of a group of adults who have been learning to swim for the very first time as adults at the Foyle Arena in Londonderry.
According to official figures, swimming is the most popular sport for adults in Northern Ireland but the thought of diving in can fill many people with dread.
As many as one in every four adults in the UK struggles to swim for 25m (82ft) unaided, with many having been put off learning by a bad experience or a lifelong fear of water.
Adult swimming lessons are offered in most swimming pools, but what pushes late learners to finally take the plunge?
Brian Carlin has always had a fear of water but decided to learn after missing out on holidays.
He never learned to swim when he was younger because there was no pool close to where he lived.
"We didn't have any pools nearby and I had a fear of water anyway so I was never inclined to learn.
"When we went on holidays, I made excuses not to go into the pool.
"I could just about manage a few strokes but I was nervous about being out of my depth."
'Seeing my wee ducks off'
Brian credits the instructors with building his confidence in the water and helping him to overcome his fear.
"Everyone has a different level of ability and you progress at a different rate," he said.
"The instructors help build up your confidence step by step.
"They have made it fun and enjoyable while we learned to master the basic techniques.
"I'm moving on to an improver's class now. I'll keep it up but I don't think I'll be in the Olympics any time soon!"
One of the group's instructors at the Foyle Arena is Stephen Graham, who has been teaching adults to swim for many years.
"It's about helping them to get over their fears, keeping them relaxed in the water and helping them to build their confidence," he said.
"At first, it's baby steps - getting their face in the water, getting comfortable standing in the water and holding on to the wall.
"At week one, you'll see the white knuckles hanging onto the wall but by the end of the classes they can swim across the pool and back."
Stephen said he gets great job satisfaction from seeing the adult learners progress throughout the sessions.
"It's phenomenal watching their confidence and ability grow from week to week," he said.
"Once they get over that initial fear factor, they really thrive and learn to enjoy the water.
"By the end of the lessons, I'm like a mother duck seeing my wee ducks off into nature."