See http://www.danuu.com for a stock cover but I'd suggest going to a boat canvas shop. I use Dart Canvas in Ft. Lauderdale (probably the best such shop on the east coast) but any shop can do the job. Take the kayak and ask for a fitted cover. Don't use stretchy material as it will ripple and be noisy in the high winds associated with freeway driving. If the shop is not use to making such covers remind them to sew a red 1'x1' flag on the rear end of the cover and you're all set. SEEYA Jack

I have a danuu cover and I would highly recommend it.  Very high quality and easy to take on and off.  

There was a guy out here on Maryland Eastern Shore that makes plane covers and he was looking to provide covers for kayaks as well.  I'll see if I can dig up his email for you.  His covers looked really nice from what I remember.

FrankP

We made a cover last December utilizing two form fitting socks composed of solution dyed, water resistant (breathable) material.  The aft sock goes on first and extends into the cockpit area.  The forward cover pulls over the aft one with an overlap.  There is a webbing belt in a pocket sewn into the trailing edge of the forward sock.  Belt tension is adjustable, but requires little adjusting once initially set since it also uses a black plastic buckle similar to what is used to secure CLC external hatches.   The belt tightens at a point on the kayak that is aft of max beam.  Releasing the buckle allows removal of both covers as the aft sock is uncaptured from the forward section.  We found two shorter socks a simpler design and less hassle than one large cover and associated closing mechanisms.  A flap covers the buckle and the little bit of webbing (belt) that would otherwise be exposed to direct sunlight.    Hopefully, Dave will bring it from Fla. to OkoumeFest this year.  

For my Wood Duck 12 I considered sewing my own cover.  But the cost of the materials alone for a do-it-yourself sewing job exceeded $100.  Then I found a 12 foot cover that fits the wood duck perfectly on the Sam's Club website.  The price has gone up since ast year--now its about $50.  https://www.samsclub.com/shopping/navigate.do?dest=5&item=343540&pCatg=5523   

My Wood Duck 12 lives on top of my Subaru all summer, and the cover protected it from sun and road grime.  The sun did bleach the dark green cover to a pea green in places. Better it bleach the cover than the kayak though.

The hand made cover by BobE sounds beautiful, and certainly a tailored cover will fit your kayak better than an off the rack version intended for wide beam canoes like Grumman. But I expect a cover to take the punishment I want to spare my kayak which means it won't last forever, and cheap makes a difference.