I just purchased a Magellan Meridian Marine off Ebay for 100 bucks lees than the retail at Boaters World, WestMarine, or the other retail outlets. I have only one complaint...the cheapos give you the info manual on CD ROM and you have to print it out. However, the quick start guid enclosed with it was enough info to get me started. I love the fact I can mark new deadheads in Clifton, find my EXACT spot to anchor at the Eagle's Nest, or follow the channel out of Deep River in the fog (which is tricky for a novice like me without this unit).

Old Man, I'd say they are not a total neccessity, but their value in terms of safety is fairly substantial. In low visibility you can use your senses to look around the immediate vicinity for problems rather than worrying about your heading or whether you are close to the correct bouy). Its all right there on the screen and pretty damn accurate to boot.