From the first Sunday in May the swim club meets at the jetty at 08:30 (sample). The lake is cold, around 10°C early in the season, so most swims are a few strokes out and back.
A sauna host stays on the jetty, and the Finnish sauna is heated from 08:00 for the club. Bring a swimsuit, a hat for after and a warm robe.
The swim is included in a day pass. Sign up at the desk the week before.