Cavalier King Charles are spaniels and MOST can swim.Make sure that they start at a young age. Dogs in general can make bad decisions when they swim. If they fall from a boat, they may swim away from shore rather than to the closest shore. You can take cavaliers kayaking, but they shopuld wear life vests. Dogs also get over tired when playing fetch and can swim out to far and not have the strength to swim back. Cavaliers also have long ears that are prone to infection if not dried properly.