Most sessions run twice a week. It’s not compulsory as many sailors have other sports. But sailors do progress much quicker if they can attend more sessions.
We do strongly encourage other sports, however, which is great for fitness and many other skills. Studies show most athletes should not specialize until they are at least 14 in any sport, let alone in a specific sport. An example is a swimmer won’t know their best stroke until around 14. Runners won’t know their preferred distance until 14, Ball sport positions on courts and fields are the same. Sailing can be more diverse but there will be many options at around 14 including single-handed sailing, doubled handed, windsurfing, foiling, kiting, keelboats etc,..