David, the Carlton with the serial number 11809 is 19' long, not 17'. The only canoes with 11x09 serial numbers that are are 17' long are 11109, 11209, and 11509.
I've attached below copies of the build record for the four serial numbers -- if any of them are a clear match to your canoe (because of features like keel, outside stem, deck and thwart material, etc.), please let us know.
These scans and several hundred thousand others were created with substantial grants from the Wooden Canoe Heritage Association (WCHA) and others. A description of the project to preserve these records is available at
http://www.wcha.org/ot_records/ if you want more details. I hope that you will join or renew your membership to the WCHA so that services like this can continue. See
http://www.wcha.org/about-the-wcha/ to learn more about the WCHA and
http://store.wcha.org/WCHA-New-Membership.html to join.
It is also possible that you could have another number or manufacturer if none of these descriptions match your canoe. If that is the case, photographs of the serial number, deck, side profile, seats, and other details would be helpful in identifying the canoe. Feel free to reply here if you have any other questions. Feel free to reply here if you have any other questions.
Greg