We bought a Sailrite Ultrafeed LS-1 Walking Foot Sewing Machine when the ShadeTree boat awning needed to be replaced. A new awning would have cost as much as the sewing machine, and we figured that we'd be able to do other projects as well.
The first project was a small awning for the aft cabin. It is a square piece of green Sunbrella with hooks on all corners to enable it to be streteched above the aft cabin hatch, and after three years it still looks and works just fine. The stitching looks as if it was done by a drunken sailor...
The second project was a cover for the center section of the boat: it spans the 12 feet between the masts. This awning takes all of three minutes to take down or put up, and those activites can be accomplished by one person. It's a great design, but needs a ketch rig. Stitching got a bit better, but I screwed up the tensions and had to have the machine serviced.
Fast forward two years: we decided that the binnacle needed decent protection from the Hawaiian sun, so we built a cover based on a sail bag. This project took only one day and fit perfectly.
Now, I've purchased three canvas-work books and and I'm all juiced up to do a bunch of other projects, including a mizzen sail cover, forward quarter cover, sheet bags, curtains, a windlass cover, replacement cover for the outboard, etc.