At least here locally, 10-codes are a thing of the past.
With the advent of 800 mHz radios, voice is as clear as a cell phone call.
Some jurisdictions are moving to 'text' communications, meaning speak the words that you want to relay.
Basic marine radio etiquette is:
Channel 16: Distress, Safety and Calling. Find your party and agree to move to a Non-Commercial channel.
I use channel 16 liberally and often for information: "There is a 10" dead-head log at mile marker 826.3" or "(my location) radio-check" or "Green with Envy calling Ladybug Soup", after response, then say "Go to Channel 6-8" or "What time is sunset today?"
As long as channel 16 is kept clear of clutter and chatter, requests for info or seeking another operator is usually tolerated. Once in a while, you'll here a rookie chatter-boxing on 16 and if the Coast Guard is in the vicinity they will request that the channel be kept clear.
It is fun to listen to the commercial barge traffic if your radio has a scan mode.
Water patrol usually moniters Marine 16 while on the river.
My understanding is, at least for our use on MN/WI inland lakes and St. Croix/Mississippi, Marine use is the same as CBs from the 70s. Just a little tighter on which channels can be used for which need.
Channel Info:
http://www.navcen.uscg.gov/?pageName=mtVhf
