Enroll in semi-private swim lessons in San Francisco at Waterworks Swim School. Semi-private swim lessons provide a lower cost alternative to private lessons with the benefits of learning in a small group. Semi-private swimming lessons pair together two swimmers ages 2.5 and older with one swim instructor, allowing swimmers to learn from their teacher and each other. Learning with a friend, sibling, or someone of similar age and ability can be a fun way to experience swim lessons.