To expound a little on what little I know about GMRS.

First of all detachable antennas are allowed on GMRS but not on FRS. The 15
channel FRS/GMRS radios like the Cobra PR1000 and Memorex MK1995 have a
detachable antenna as do several others. Especially the higher end GMRS
only models. Replacing the stock antenna with a 1/4 wave antenna reportedly
substantially increases range. The 22 channel radios do not have detachable
antennas.

Second according to the BVI Tourist Board the BVI government has taken no
position on the use of FRS/GMRS in their waters.

Third the GMRS license cost $80 and is good for 5 years. One license covers
the named individual and his or her immediate family members, including a
spouse, children, parents, grandparents, aunts, uncles, nephews, nieces, and
in-laws.

1.5V alkaline batteries will output significantly more transmit power than
1.2V Ni-Cad/Ni-MH.

The maximum power for GMRS is 5 watts but the only reasonably priced 5 watt
model I can find is the Midland GXT500. But 2 watts vs. 5 watts in only
about 4db. A good antenna and high quality construction can have a much
larger effect on range. I have never been particularly impressed with
Midland's quality so I am hesitant to try one.

Some things I don't know.

Over what terrain do they test these things to come up with the range
claims? If a set advertised as "5 mile range" will only work within 2 or 3
miles line of sight with no obstructions over water the only place I can
think of that would have better conditions would be the Bonneville Salt
Flats.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

On Mon, 9 Jan 2006 08:03:37 -0500, "Glenn Ashmore"
wrote:

Over what terrain do they test these things to come up with the range
claims? If a set advertised as "5 mile range" will only work within 2 or 3
miles line of sight with no obstructions over water the only place I can
think of that would have better conditions would be the Bonneville Salt
Flats.

=========================================

FRS is pretty much line of sight or close to it. Any significant
obstruction will greatly reduce the range in my experience. To get
reliable range of any distance at these frequencies you need a
repeater type infrastructure with an antenna at higher elevation.

If you have an FRS with connections for external audio in/audio out,
you might be able to extend your range somewhat by hoisting the radio
to the top of the mast on a flag stick, and running audio cable back
to deck level.