If you check out Bizer's web site, he is checking on interest in porting his map data to Garmin-compatable format. These handheld GPS units can be used in the car, for hiking, and in the boat and have come down in price significantly. The portable flexibility means you can buy one unit and use it in any boat, car, or on foot.
The default map data on these units do not accurately show all the islands, so the ability to import Bizer map data would be great.
If there is any interest in getting the Bizer map data for Garmin, please make sure you let him know or it won't happen. Here's the link to the info and how to respond......
http://www.bizer.com/