VHF range?

Hi, I'm considering to buy a handheld VHF - or to be more specific - a Cobra HH475 (max output: 6W). I understand that several yakers use a Cobra with similar output.

Do you have any practical experience with max range? It seems possible to replace the short antenna with a slightly longer version and that may extend the range. These VHF radios are fairly expensive here (x2 as compared with US prices), so comments and suggestions are most welcome!

I posted some info on range in this thread ... http://www.northwestkayakanglers.com/index.php?topic=7257.0

-Allen

I posted some info on range in this thread ... http://www.northwestkayakanglers.com/index.php?topic=7257.0

-Allen

Thanks, Allen! Very useful information.

I should have put more effort into a forum search before asking! ;-)