I've been wanting to take full advantage of my VHF this year so I've been tinkering with it. I've found some good info from BoatUS about the Digital Selective Calling (DSC) features. If you're not sure what it is or just aren't aware of it's advantages, take a look at the 1st link below. It takes about a half our or so to get through. Aside from the safety features of DSC, most DSC radios will allow you to store 20 or more of your buddies MMSI. You'll be able to poll their Lat/Lon without ever having to blast it over the radio! Or you can call them regardless of what channel they're on and can have them switch to a channel of your choosing (i.e. instead of 68, you put them on 71 and talk in a less crowded forum). Hope you find this useful.
http://www.boatus.com/foundation/dsc/player.html
And if you don't have your MMSI yet, you can get that here:
http://www.boatus.com/mmsi/instruct.htm
Keith