Swimming lessons are now a part of our Saturday routine. They both love it and Mees now is very comfortable crossing the pool doing the backstroke and the front crawl. Funny enough they do not teach the regular breast stroke or "schoolslag" at the swimming school we attend (not sure it is the same for England) because it is a "natural stroke", and they reserve it as a pannick button stroke.
Anyway, their dissapointment was big when the pool was closed for maintenance, so they opted for the bathtub instead.