In US waters, you don't need a license for Marine VHF gear. However, if you are not actually in a boat, on the water, you are supposed to have a station license, and it's only for communication to marine operators. For example, a Marina might have a station license to talk to boats looking to reserve a slip or request a launch pick up. The FCC doesn't allow, legally anyway, the use of Marine VHF for land based comm's. The band they are on has characteristics similar to the 2 Meter amateur VHF band, so it would be good for local point to point comm's, but, it's not really intended for that.
I guess I'm back my original suggestion...that many have echoed, considered getting your ham license