Island at the End of the World by Henri Crouzat

Shipwrecked when their hospital ship is torpedoed, a young officer of the French Air Force and three English nurses find themselves marooned on a tiny island in the Indian Ocean. There are Joan, a nymphomanic; Victoria, a lesbian, and Kathleen, a quite ordinary girl. Slightly macabre, as not everyone lives.

This book was made into a French film in 1959 titled L'île du bout du monde, directed by Edmond T. Gréville, and was later brought to the U.S. as a movie called TEMPTATION.