The eighteen celebrity recruits are transported by high speed rib to the new Hell Week base, an abandoned military base in east Cork. Waiting for them at the jetty are the course instructors (DS), who give them a short, sharp blast of what they can expect. The recruits, who for five days will have no contact with the outside world, are left in no doubt this will be an experience like no other.

The next phase of the course sees the recruits pushed to their absolute physical limits, with back-to-back events including boarding a large ship as it sails through Cork Harbour

Army training challenge in which civilian recruits are put through a gruelling special forces selection course

The challenge continues with a boat race across the busy shipping lanes of Cork harbour, before the recruits are paired off to box one another in two one-minute bouts

The recruits start the hardest test on the Hell Week course - Foreman Aftman - a timed mountain march with over 50kg of kit of their backs

The programme reaches its final phase. Of the 18 recruits who started, only four candidates now remain, and the courses culminate in one final event

Twenty celebrities from the world of sport and entertainment take on the army training challenge and are put through a gruelling special forces selection course

The celebrities continue their army training challenge in which they are put through a gruelling special forces selection course

The celebrities continue their army training challenge in which they are put through a gruelling special forces selection course.

The DS continue to pile the pressure onto the 11 remaining recruits - David Gillick, Peter Finn, Billy Holland, Aisling Daly, Setanta O' hAilpin, Johnny Ward, Eric Donovan, Eoin Cadogan, Rebecccah O'Rourke, Fergus McFadden and Ciara Griffin.

Following the gruelling events, 11 recruits remain. For the recruits who pass the test, the relief is short-lived as the DS arrange another equalling terrifying activity that very few people outside of Special Forces Operators will ever experience.

The recruits start the hardest test on the Hell Week course, Foreman Aftman, a timed mountain march with over 50kg of Kit of their backs. This is as tough as it gets.

Of the 20 recruits who started the course, only four now remain. The course culminates in one final event - complete the mission and they will have passed