125 rugby tackles in freezing sea for poignant campaign

Warning: This article contains discussion around suicide and depression.

The freezing February water bursts over Paul Pook's head and the former professional rugby player grits his teeth against the icy chill.

He is launching himself at rugby tackle bags in the shallow depths of the sea on Eastney beach in Hampshire.

Every tackle the 57-year-old makes symbolises a point scored in Thursday's Six Nations opener between France and Ireland.

The idea behind the stunt is that, on average, 125 points will be scored during a Six Nations week. The same amount of people will take their own lives by suicide across seven days in the United Kingdom.

"For me, that physical pain I feel going into the sea doesn't come close to the emotional pain that someone is feeling when they're suicidal."

Although his life has turned around now, the former Ireland rugby fitness coach described himself as a "functioning suicidalist" over the past 20 years - similar to a functioning alcoholic.

"Twenty-four hours after Ireland won the Grand Slam - when I was their head of fitness - I was self-isolating in a room, but no-one knew," he said.

"I was able to function while wearing a mask, pretending I was well when I wasn't, and that takes its toll."

'We didn't know about significant concussion back then, we just brushed it off'

At some point over his 30 years of playing rugby for several Welsh clubs and for Wales Sevens, Pook suffered a brain haemorrhage.

He knows this because it was discovered during an assessment.

Neurological tests showed Pook had post-concussion syndrome and disrupted emotional circuitry.

He said it explained his severe bouts of depression and suicidal thoughts.

"Traumatic brain injury or concussion can significantly impact somebody's emotional regulation and can cause depression, conditions like dementia and motor neurone disease," explained Lauren Vickery, a psychotherapist at Sporting Chance.

Pook is now part of the class-action lawsuit that more than 1,100 former rugby players are taking against the sport's governing bodies.

They allege the governing bodies were negligent in failing to take reasonable action to protect them from serious brain injuries. The governing bodies deny any liability.

Yet Pook still has a love for rugby and believes the sport can save lives.

"We didn't know about significant concussion back then, we just brushed it off," he said. "I hope it would never happen today, because the rules have changed."

For the past eight months Pook has been having therapy with Vickery and says his progress has been "miraculous".

Therapy has prompted Pook to found Tackle Suicide CIC, a non-profit organisation which campaigns for suicide prevention, raises awareness of mental health in elite rugby and fundraises for amateur rugby players in need of counselling.

Pook will make another visit to the sea this weekend after Scotland's match against Italy in Rome and England's game with Wales at Twickenham.

If you have been affected by any of the issues raised in this story you can visit BBC Action Line.