Another Option - Plan B
What about this Plan B idea. This spring take a look at something like a Raleigh SC40, or something in their "Sport Comfort" series, and see what you think. It's an aluminum frame (read: 'no rust') and weighs about 32 pounds. To make it 'smaller', because it doesn't fold, the wheels and seat have quick-releases so these can be removed. Wrap the wheels in an old blanket and stow them below somewhere while underway. The frame by now would weigh probably around 25 pounds so it would be much easier to hang on the stern rail.The components like the deraileurs, brakes, and the crank set are corrosion-resistant so they should take a number of years to degrade.The fatter tires are good for gravel and dirt surfaces, the 26-inch wheels good for stowage down below, and the light frame weight good for overall handling.Puting the rear wheel on may be a bit of a challenge at first but after a few times you'd learn all the tricks for easy assembly. I picked up a previous-year model at the bike shop brand new for around $200, + or -, several years ago and it's been the greatest for ground transportation. Sure beats the heck out of walking!http://www.raleighbikes.com/ http://www.trekbikes.com/ The lighter weight frame makes it much easier to handle. Anyway, this is something to think about.