http://cumberlandcrappie.com/accessories.html

I use these, and I like how they allow you to pass between the front seats. Really helpful in a narrow boat. Might not be as big of a deal if you use a 20 foot glass boat. I have an 18 foot tin boat, and space/maneuverability is a big issue.

http://cumberlandcrappie.com/files/IMG_588211.jpg