In most areas channel 16 is the call or “hail” channel. Once contacted, then the conversation is moved to another channel. In some areas with high traffic, 9 is used as a call channel also. There are channels that are set aside for:
Ship to ship
Base to ship
and
Emergency channels
Refer to your owners manual for these.
In the metro area not many folks pay attention to these with the exception of the call channel.
The US Coast Guard monitors 16 and uses 22 for announcments. Generally they announce the announcement on 16..and move to 22 for the actual message.
Channel 14 is used by lock and dams along with lift bridges. Many times they monitor 16 too…but not always.
The directions that come with your unit will be very helpful in this reguard.
There are a bunch of us buddies that monitor channel 69 on the St Croix and on the ‘sippi the other buddies use 82. It’s helpful to know how and to use the scan feature on your radio as I can monitor 16/14/69/83 plus have the weather alert on.
Good Luck!