Go check out ADVrider. The Panama-Columbia leg is often done on sailboats with bikes on
deck.
FWIW I'd go 250-400ccs(can be found 300lbs or less) if you plan to do some serious distance riding. Or a CT110 if mostly local. Or a Yamaha 125 if mixed.
If the Yamaha 125cc can go RTW, why not use it on your
boat?
Likewise the CT110.
Both those have been ridden either RTW, or
Australia to London
England overland. Good enough for poking about on shore.
FI(no carbs to mess with) stone axe reliable too.
http://www.motorcyclistonline.com/es...2_0104_moscow/
Here's a couple who stuffed a CX500 in the
bilge for a few years...
"What we really needed was a
boat. We looked for a working
passage, but couldn't find a ship traveling that
route. Then, one day, Tania walked into a marina and found a 31-foot, 35-year-old wooden sailboat--one full of holes. We knew absolutely nothing about sailing. But with the last of our savings we bought the boat, fixed the holes, dismantled our bike, stored the pieces on board, and sailed away from the war in the Middle East by traveling West--across the
Atlantic Ocean to the United States.
"