If your boat is trailered-
I considered a pre-made full cover and the associated cost/ warranty for awhile and decided to go with a plain old tarp 24' X 16'. I made up a line that goes from both FWD cleats, across the windshield rail and back to the steering bracket on my Yamaha and drape the tarp over and bungee to my trailer. I made up a custom smaller tarp (using Gorilla tape and tie wraps) cover for my engine. I put the engine cover on first and pull theAFT end of the boat cover over top of it. We had a 2" shot of rain last Friday in 2 hours and no water stayed on the tarp! The free-flowing air prevents mildew and I can climb in and out easily if I need to get any gear out for fishing on someone elses boat. I can install the whole thing in leass than 15 minutes. I've been through 2 tarps in 6 years, not to shabby seeing how I ripped the first one by being bull-headed while installing it.
I know this is an old thread, but I'm considering the Carver boat cover mentioned in the above post for my 1800. I don't have a bow rail though. Does anyone have photos of how it would fit without the bow rail? I don't want it to be too lose and collect and pool rain water.
Eastern Marine doesn't seem to sell the Carver covers anymore, but here's a link to it on Boat Covers Direct: