Frank Redmond (PETER MULLAN) has worked most of his life at a Glasgow shipyard and thus isn't happy when he's laid off along with others, such as his younger friend Danny (BILLY BOYD). Upset about that and still haunted by his seven-year-old son's accidental drowning decades earlier, Frank finds his middle-aged life without purpose or direction. It doesn't help when his unemployment case worker turns out to be his daughter-in-law Angela (JODHI MAY) who supports her unemployed husband Rob (JAMIE SIVES) and their two young sons.
Frank and Rob don't really get along, so he spends most of his free time at the local swimming facility with Danny and their two friends Eddie (SEAN MCGINLEY) and Norman (RON COOK), unaware that his wife, Joan (BRENDA BLETHYN), is secretly try to earn her bus driver's license so that she can support them.
One day, while on a "booze cruise," Danny points out that on a clear day one can see France, and Frank suddenly gets the wild idea to swim across the English Channel. His friends think he's crazy, but soon throw in their support behind him and Chan (BENEDICT WONG), a local restaurateur who's offered to be Frank's coach and motivator. After their borrowing of a boat from Merv the Perv (TONY ROPER) doesn't work out as intended, they manage to get Mad Bob (PAUL RITTER) to serve as their captain to navigate the twenty some miles between the two countries.
As various family relationships come to a head, Frank continues to train for his big swim and eventually sets out on it, unaware of how it will affect him and his friends and family.