Also, not all canvas work is the same in terms of workmanship, materials, and quality. I'd ask around for references in your area, and walk the docks and see whose canvas looks nice. I'd be specific on how you want it to look too. Some dodgers on boats look like a two-story pop up greenhouse, whereas some others may look a little more elegant. A hard dodger is a nice upgrade if you can afford it. Same with hard vinyl windows and Stamoid fabric. It's expensive, but will far outlast Sunbrella. Who ever you go with, be prepared for sticker shock as it's typically a lot more expensive than you'd think.
Mark