Sink or Swim (1980)

Brian Webber lives on a leaky houseboat in London. He's trying hard to make his way in the world, thus far with limited success. His girlfriend, Sonia is a very serious minded young woman who is passionate only about things like vegetarianism and ecology. When Brian's younger brother Steve arrives in London looking for somewhere to stay, his lazy, cynical, noisy "Northern lout" attitude disrupts Brian's already messy life.