o8LSV i found this at bas pro for 10 dollars and would work perfect for out situation.place the head inline with the track fins and if you forget the plug it will help by having a teflon ball that stops water from flowing into the boat. The ball is held into place by a taper on the top and a stainless rod on the other so there's no way to loos it

http://www.boatersoutlet.com/garboar...eadedbase.aspx