Re: CB on a boat as well as VHF?
For many, many years my boats always had both a VHF and CB radio, but when I moved into a big boat 3 years ago I didn't bother with the CB.
I did however, install a second fixed VHF with antenna for redundancy.
I think it really depends on your boating area. There's a lot of lakes that don't have much VHF activity, and in those cases it might be good to have a CB onboard.