Tommy Watson and Lydia White

Having met on Facebook a year ago, office manager Tommy and singer Lydia's relationship is about to face its most extreme test to date as the Atlantic comes between them.

Gareth and Mason McLaughlin

Slim twins Gareth and Mason have signed up for a show where one must plunge into the cold ocean and potentially carry lead weights. What on earth could go wrong for the London students?!

Chris and Dave Sansom

Father Dave and son Chris describe themselves as "the most competitive family you will ever meet." Which is just as well when they come to realise that having done a triathlon and an iron man is plain sailing compared to The Wave.