Go with a dedicated marine VHF radio. There are some commercial VHF LMR radios that do have the FCC Part 80 specifications, but they won't gain you anything if all you need is marine VHF.
Best antenna you can install, up as high as you can get it.
Crimp AND solder all your power connections. Follow up with liquid electrical tape or marine grade heat shrink tubing. Corrosion becomes a real issue and I've seen to many issues from poor connections.
While most have it, you want a radio with "Dual Watch". That lets you use one VHF channel while still having it monitor channel 16.
Most of all, learn how to use it properly, what to say, how to say it.
West Marine usually had some good house brand radios that were rebadged name brand stuff. Just stay away from the Random Chinese radio du-jour. You don't want to have your life rely on a $25 radio.