Tidal Races and Overfalls Weekend If you haven't had enough of the races already or you need some more tuition/confidence building, this is the course for you. 2 more days in the wave machines of Penrhyn Mawr and North Stack. We have found that the symposium tidal race and overfall classes are more of an experience than training course due to the large numbers of people wishing to partake in them. During the symposium weekend our focus with such large numbers is invariable safety. So to do our coaches justice in their ability to coach you well in the overfalls, we now provide an extra 2 days for folk to receive much more individualised training that focuses on taking you from where you are now to where you want to be as a rough water paddler.