: I am planning to install one as well. For the cost (see link) I
: don't think I'll bother with homemade.

: www.handpumps.com/guzzler400S.htm

I installed a foot-operated Guzzler. On the plus side your hands & paddle are free to keep the boat stable 'till you get it pumped out. On the negative side your leg or legs will be very tired and it will take longer than you want before the boat is empty.

There is a picture of mine here: http://www.flickr.com/photos/9239236@N05/611680021/

Ric