Asked to leave his floating home, a Scottish hamburger factory ship, Woody Legg is retired to the Old Boathouse, a retreat for unwanted sailors run by a very strict matron, Frauline Stropalotti. Woody and the boys plot to escape on a disused and abandoned sailboat now renamed the Prawn Cocktail. 

With the help of the Putney Sewage King, his associates the Bog-Whoppits and the Nincompoops, Woody and his friends wrench the Prawn Cocktail out of a muddy creek and back onto the sea.

They consider themselves to be twenty-first century buccaneers and, along with a worldwide map of Primarni stores, go in search of old and hidden treasures.