design help

I built a cardboard boat and raced it against other cb boats last weekend. I smoked them all! My boat is 20" wide, 11' long & 12" tall. The sides of the boat taper from the front to 5' back. The back of the boat is straight. Since I know nothing nothing about design rules or fluid dynamics, can someone give me some general design facts that might help this boat go faster? The competition will copy my design and use it next year, so I must evolve! Thanks, David. davidllangford@yahoo.com

[Willallison]

David, can you give us a little more info -
what powers the boat?
Are there any length / beam restrictions
Apart from the cardboard, are other materials allowed
etc

Assuming you had to paddle the boat, general rule of thumb is that the longer and narrower the boat is, the faster it will go.
Also, the lighter you can make it, the better. Shape and construction detail can contribute greatly here - a monocoque structure with rounded sections would possibly be best. If you look at the way rowing shells are shaped, you will get a good idea of the best shape. Your boat would probably do better if it narrowed towards the transom as well as the bow.