I'm never quite sure why folks make a distinction between chartplotters and handhelds. HH are simply smaller chartplotters. If your eyes can stand the smaller screens, which are not that much smaller, then save a lot of $$ and have flexibility with a HH. Garmin's quite good GPS Map76Cx and Csx are on sale for more half off what I bought mine for a few years ago. Of course, you still have to get the charts, but the ones they are offering now have a lot more coverage for the same amount of money they were charging for just a few years ago. You're sailing where there aren't a whole lot of buoy changes. Go into a West Marine (there's usually one somewhere near you or use your Xmas drive to visit family and find one) and check them out. The tremendous cost difference for chartplotter, in my view, is wasteful. Another thing to consider is that as computers and all those iThingies get more popular, the "marinized" chartplotter, which only does one thing, may be going the way of the dodo bird.
Stu,
While I agree with you on the iThingie thought, I do feel there's big difference between plotters and HH units. Maybe I over-think this because I'm in the GPS/nav business, but:
1) Most HH have very limited marine nav capability. Even simple things, like a 5-minute plot line are missing from hand-helds. More advanced things, like auto (or smart) marine routing over digital cartography are impossible to find in handhelds. Two reasons for this, 1) they spend more time/money adding things like geocaching to the HH units, and 2) that do not want to compete with their plotter business.
2) Lack of interfacing. A plotter will share its location data over NMEA, and pull AIS and DSC requests from the network. HH cannot do this. (unless you add a cable and bracket... then see point 5)
3) Designed for hardwired power. The reliance on small AA batteries makes for dim screens (measured in NITS) and lower power processors that redraw maps slowly on HH units. They will always be down the curve from plotters.
4) Typically lacking a speaker (or its small). Making alarms hard to hear.
5) Price. A good HH might run you minimum of $250, but add 50 for base and cable. $300 into it and you still have the small screen. For $350 you can get something like the Garmin GPSmap 421.
http://www.amazon.com/Garmin-GPSMAP...6?s=electronics&ie=UTF8&qid=1324313213&sr=1-6
HH units have their place for sure. And they will draw an X at your location over a map with the best of them. So small boats sure. and I'd advocate always having one on-board for backup on bigger boats. But plotters they are not.