These sites come in helpful for traveling internationally by motorcycle www. horizonsunlimited.com
www.advrider.com
http://www.hostelwunderbar.com/sailing_trips.html
(hostelwunderbar is run by motorcyclists and they keep an up to date schedule of boats crossing from Panama to Colombia that will take motorcycles).
http://www.smellybiker.com/
This guy is well known for the World Map software he makes called "WanderLust" and it is compatible with Garmin gps. Also a great site for travel information.
http://matadortravel.com/travel-community/nicaragua/SalCar/travel-blog