I have the Uniden Atalntis and have gotten aas much as about 6 to 7 miles from it. A lot depends on how far you will get; such as how many others are on the air, etc. My range is with no one on the air.
Now the Atlantis I have is rated JIS4 waterproof which means that casual splashing and such will not hurt it. In fact, I use it in my jayak and it is ALWAYS wet in there. Their next model up is the Voyager and it is rated at JIS7 or 8 which means that it will work up to about 10 feet under the water for about 30 minutes with no harm.
The one I have is $99 and the Voyager is $149. Good radios. I really like mine. Of course, you can spend a lot more for about the amse preformance, ut with a couple of extra features. It all depends on what YOU want in the radio.