My boat had a CB when I bought it, I think they used it with his fishing buddies, I removed it and added a 2nd VHF, just did not see a use for the CB on the water.
Up here in the Cook Inlet CB has been the radio of choice for the sport fishermen for years. Some charter boats use it to. Channel 33. Also the commercial fishermen use it (33) when they are on the water. Lots of jabbering going on. I have a CB in my truck so I can communicate with fishing boats about weather, fish location etc. It works well.