I work for a charity and outdoor activity centre in Cornwall http://www.bfadventure.org/activities_canoeing_cornwall.html and we use former granite quarries to teach canoeing which makes it much easier for clients to gain confidence in their ability to control the boat as they are in a sheltered environment. Once they feel safe we then take them to the open water going on expeditions i.e. down the River Fal. Especially the young people we work with love these trips but they are also great for families and adult groups. Some people also learn how to Kayak in the same way. Here is a video of one of our great trips http://www.facebook.com/video/video.php?v=440681536828