Fourteen Royal Navy divers will attempt to walk 26 miles underwater in kit weighing 40kg for charity.

The mine clearance divers from Fleet Diving Squadron at Horsea Island in Portsmouth hope the punishing challenge will raise £5,000 for The Royal Navy and Royal Marines Charity (RNRMC).

The divers will start the marathon on Friday (4 September), with each pair taking it in turns to walk one kilometre in six metres of water in the giant lake at their base. They aim to complete the challenge in 30 hours.

Their equipment includes lead-lined boots, an air cylinder and a 17kg helmet. They will pull a rigid inflatable boat which will carry three support crew and back-up equipment.

Confident

One of the divers, Leading Diver Duncan Watt, 37, said: “It will be extremely tough – both mentally and physically, especially the last ten or so hours. We haven’t had much time to do specific training for this because of our busy day jobs, but we are all confident that we can pull this off.”

Laura Young, RNRMC Fundraising Executive, said: “This is by far one of the more eccentric events we’ve been involved with and we can’t wait to see how the guys get on. Taking part in a marathon on dry land is hard enough as it is, let alone being underwater. I wish them every success.”

The charity has already shown its support for Royal Navy divers at Horsea Island. This summer it supported a families day for the Defence Diving School and helped fund an outside recreation area and refurbishment of mess accommodation.

Donations to the challenge can be made at http://uk.virginmoneygiving.com/fleetdivingunit1

Note to editors: Media are invited to film and interview the divers at the start of their challenge. Those wishing to attend must arrive at the main entrance at Horsea Island, Portsmouth, at 11.30am where they will be met by a press officer. Names of media attending must be with press officer Simon Smith by 2pm on 3 September. Contact 02392 723025 or simon.smith761[at]mod.uk.