16/09/2012 11:30 BST | Updated 16/09/2012 12:45 BST

Underwater Cycling World Record Broken By Two Ex-Royal Marines At Southampton Boat Show

We already know the British are the best in the world at cycling and water-based sports such as sailing and rowing - and it turns out we're also brilliant at combining them, because two former Royal Marines have set the world record for cycling underwater.

Former Marines Chris Sirett, 54, and Brian Stokes, 40, donned diving equipment, dropped into a tank and cycled for 100.13miles in 15 hours.

They achieved the remarkable - and bizarre - feat at the Royal Marines Stand at the PSP Southampton Boat Show.

Water bizarre challenge: The divers pedalled for 15 hours

The charity challenge began at midday on Saturday and continued until 3:38am on Sunday.

The funds raised on behalf of charity Commando 999 go to the Royal Marines Association.

Mark Scoular, founder of Commando 999 said: “As with any world record attempt as physically demanding as this, safety is always a priority. So, at 3:38am after a solid 15 hours underwater, the attempt was bought to an end after being deemed too dangerous to continue by the safety team. The divers were lightheaded and suffering from vomiting and nausea.

"However, Chris and Brian have set the World Record for the furthest distance cycled underwater. They have raised thousands for the Royal Marines Association and we are very proud of them.”

The divers will rest for the remainder of the weekend before returning to the Southampton Boat Show for the rest of the week to continue to raise funds.

Attendees can have a diving lessons with Chris and try underwater cycling.