Well Kieth, I'm not sure if you've splashed (
) out on the 12 yet but here I my thoughts!
I wanted a GPS that could obviosly give a LAT and LONG if I got into trouble and had to report my location, however like you I stick close to the coast and don't need it for course planning in the middle of the open sea!
So I thought I would plump for a Garmin Map III +. I think this is esentialy a 12, but with a slightly better screen - and the real benifit is the built in Maps - and they are amazing (for land use)
Basicly if you by a Europe model it has basic road maps for the whole of Europe. When I say basic they are still very good with Motorways, A roads and lots of smaller roads. It also has railways, services etc stored too.
I find these maps good enough to navigate by (I've used it in France, Ireland and Gran Caneria!). I'm currently in Cork on Buisness. I have hired a car so once I found the office I added a "waypoint" and again added another "waypoint" at the hotel. These are then clearly marked on the map.
As you drive arround the map moves with your position being a triangle in the center of the map. The clever bit is the triangle points the direction that you are going, so if you are going north it points up, south - down etc. So its easy to see where you are and which way you need to turn to find your way back to the hotel.
You can also by a CD which contains A-Z level detail of every road and road name (yes, every road) You can then connect your GPS to your laptop and download detailed area maps of particular areas. Again I used to use this when I was visiting Customers and funnily enough I never got lost!
Anyway the GPS III is a couple of years old and the latest Garmin Handheld edition is the GPS 76 and GPSMAP76. One of my friends has recently bought a MAP76 - one of the benifits over the III+ is that it comes preloaded with navigation aids (bouys, lights etc.)
I know people with a "standard" GPS and when they see my "MAP" version they wish they had one because it is much more useful off the water as well as on!
Have a look at www.garmin.com
It also works well on a plane - if your sat next to the window - to see where your flying over - not much use without the map function.
Loads of information on GPS on the web - just stick GPS in any search engine
gives a very good explination of how it all works!