These kinds of sports are perhaps more for the adrenaline, nature types. For these sports, you learn how to succumb to the elements and work with them.
Sailing: G.S.Z. Mayday
Skating: G.S.S.V. Tjas
Swimming: G.S.Z.V. De Golfbreker
Waterskiing and Wakeboarding: G.S.W.V. The Bares
Waterpolo: G.S.Z.C. De Walvisch
Canoe sports: Groninger Kano Vereniging