I retrofitted a slider controlled skeg in a customer's kayak and he loves it. There is just enough friction so he can position it at the depth he wants. I followed ideas from Andy Waddington's website: http://www.pennine.demon.co.uk/kayak/skeg.htm and from Dave McKinney's photo album: http://public.fotki.com/davezpics/kayak_canoe_wooden_boats/skeg_construction/

Glen in Baie-St-Paul.