Amazing how the adjustable "wave shapers" look like the culvert that we use in the ditch! http://www.riverangels.com/ssp/gossip?news_id=69 http://www.mclaughlinwhitewater.com/ww_projects/ww_advensports_projnotes.shtml http://www.adventuresportscenter.com/index.php?option=com_frontpage&Itemid=26