Known in the original Italian as "Travolti da un insolito destino nell'azzurro mare d'Agosto." Better known as Swept Away in English-speaking countries. A film from 1975 written and directed by Lina Wertmüller. It's a wonderful story of what happens when a lower class communist winds up on a deserted island with a bourgeois married woman.
He's working on a leisure cruise boat and she's a passenger who wants to be taken to land, where the other passengers had gone without her earlier in the day. She, Rafaella, gets the communist hired help, Gennarino, to take her. The boat malfunctions and they wind up on the island, alone. This is where the fun begins, as they work their way from hatred to something that resembles love.
In my opinion, this is Wertmüller's best work.