The question:
I am looking for a radio to use hunting. 
Marine Radios are cheap and powerful. 
Can't I just use one of those when hunting?

The answer:
NO! It is VERY illegal.

Why:
From the FCC website:
Prohibited Communications 
YOU MUST NOT TRANSMIT --
False distress or emergency messages.
Messages containing obscene, indecent, 
or profane words or meaning.
General calls, signals, or messages on 
channel 16, except in an emergency 
or if you are testing your radio 
(these are messages not addressed to 
a particular station), 

Or, When your ship is on land 
(for example, while the ship is on a trailer).

Reasoning:
(1) OK let's reason this thing out...
if you have a marine radio mounted in 
your truck, it IS NOT in a "ship". If your 
truck was designed to be driven on land, not water, 
so it is "on land". Therefore, having a marine 
radio mounted in your truck is ILLEGAL!

(2) If you are carrying a marine handie talkie, 
and you are not in a boat that is in the water, 
and not walking on water, then you are "on land".
Therefore, having the marine handie talkie is ILLEGAL!

(3) No one will ever know...really? Get on the 
right frequency, and the COAST GUARD WILL 
KNOW and they do have ways to pinpoint 
where your transmission comes from.

And last but not least:
(4) But what if I am duck hunting from my boat? 
Then it's legal, right? Well, depends on what the 
communications are. If you are having valid marine 
related communications with another boater, 
boat dock, lock master, Coast Guard, etc, yep, 
you're legal. But...if you are telling your buddy 
up stream "The ducks are a comin' your way!" 
then YOU ARE ILLEGALLY USING A MARINE RADIO!

What can I do?
Well you can try these.

Citizen Band... Radio Service
FRS... Family Radio Service
MURS... Multi User Radio Service
GMRS... Radio Service
With all services ... Stay safe. Please check 
the current FCC rules and regulations for 
the legal operation of each service.