This movie is about a couple of months in the life of some ordinary Swedish people: Charlie, a truck driver who lives in a boat, his friends (some of which are musicians), and work mates. Charlie, who is a good-natured and uncomplicated person, agrees to let a woman he doesn't know stay in his boat for a couple of days. She is pregnant and has nowhere to stay. After a while, they come to like each other. At the same time, a friend asks Charlie to take part in a pro-Cuba demonstration, which forces Charlie to think over his political views.
The movie is very entertaining, if you like to see real people in real situations, confronting real issues. The script is interesting and well written, as is the dialogue. The tone is one of optimism, even joy, despite the unpolished, at times bleak, realism. A fair amount of humour contributes. As an added bonus, in the roles of Charlie's musician friends, you get to see and hear some of the best known Swedish jazz musicians of the late 60s, like Lasse Werner and Christer Boustedt. To sum up: recommended.
A final word about the politics of the movie. A previous reviewer wrote that the political views expressed in the movie are naive. This is only partly true. The opinion that socialism will make society better is indeed naive, since in practice socialism leads to a waste of resources and a loss of freedom for the individual.
However, the description of how the United States government tries to force its will on smaller countries, is not at all naive. It is right on the money. It seems that many people back in 1970 understood this better than some people do today.