CB vs. VHF

VHF is 30MHz to 300MHz. CB is 26.965 MHz to 27.405MHz

Close- but not quite the same...so you'd need a dual tuner/receiver and a transmitter all in the same box. Not sure if you'll find anything like that.

 

They are between 462 & 467Mhz. They call them "Family Radio Service" (FRS).

I have never seen a radio that can transmit & receive Marine VHF, CB and FRS.

A scanner is your best bet. Make sure it says it will receive Marine VHF, CB and FRS.

Some scanners can receive all freqs. between 25mhz & 1.3Ghz.
(With the exception of some freqs reserved for Military & Cell phones)

 

This guy is correct on the FRS freqs-which are in the UHF band. CBs operate in what are basically the "high" shortwave freqs, just below the VHF low bands, which as said above by Brunes, start at 30MHz. Marine freqs are between 156-162MHz in the VHF high band. Your best bet would be to get a scanner-they even make very good handheld ones so you dont need an install. You need a license to operate on the marine bands.

Here is one of my older scanners on the marine frequencies ( shot this vid for a radio forum) it is th US Coast guard station plotting the movement of a tanker ship out on the bay.

 

I guess family radio talkies are your choice. Unfortunately, they dont make a radio that covers marine band for cheap. They have trancievers that will do it but there again you need a license to run one because of the bands it covers. CBs and family radios are around the same price so..