When writer-director Anders Helde started writing the script he immediately thought of actor Jonas Wandschneider for the role of Rasmus. Anders Helde had first seen Jonas Wandschneider in the film 'The Substitute' (2007) and he later met Jonas Wandschneider on the set of the TV show 'Anna Pihl' in 2007. In both 'The Substitute' and 'Anna Pihl' Jonas Wandschneider played a similarly aged boy with some of the same traits and sensitivities as Rasmus in 'The Boy Who Couldn't Swim'. Once given the script and offered the role of Rasmus, Jonas Wandschneider asked if he could play the role of Nicklas instead as he wanted to take on a different challenge for this movie and play a different kind of character from those he had played in the past.
The film was shot over a total of 6 days in and around downtown Copenhagen with only a 5 man crew. All the shots of Rasmus and Nicklas cycling through Copenhagen was shot hand held out of the back of a Saab convertible.
When the film crew shot at Christiania they had to be extremely careful not to film in, or even close to, 'Pusher Street' as that part of Christiania is a strict no-camera zone.
Official selection for Indie Film Festival 2015 [Switzerland]
The opening sequences of Michael Mann's HEAT and COLLATERAL served as inspiration for the opening sequence in this film as well as its basic premise: the main character arriving in a city to carry out a mission. In HEAT and COLLATERAL Robert De Niro's and Tom Cruise's characters arrive in Los Angeles on a mission to carry out crime. In this film the main character Rasmus arrives in Copenhagen on a mission to find his estranged mother. In all three films no words are spoken during the opening sequences.