the following link is to the list of VHF channels, yes channel 16 is coastguard and you cannot talk on it unless an emergency, you can talk on channels that have non specific commercial purposes. most chatter you will here IE: guide boats and other fishermen will be on channels like 88a , 68,69,and a handful of others. most vhf are pre programed and you cannot tune frequency without an Amateur radio license EI: Ham radio ticket so UHV or ultra high frequency would not be useful to you. here is the list of VHF channels pre programed into your VHF. hope this is helpful.
http://www.csgnetwork.com/marinefreqtable.html