"James Hebert" wrote
VHF Marine Radio Communication

http://continuouswave.com/whaler/reference/VHF.html

There seems to be some confusion regarding the
calculation for radio horizon. I am afraid I did
not collect anecdotal reports from anonymous USENET
contributors, but instead relied on other sources.

Cf.: definition of radio horizon:

http://amsglossary.allenpress.com/gl...radio-horizon1

James, don't confuse 1w-rubber-duck man (anonymous "me" contributor) with
logic. Heck, after reading his story, I may pull down my antenna and replace
it with a rubber-duck. After all, I only get 20-25 miles reliable range to
surface craft from a 60' amsl antenna w/25w! This might have something to do
with small craft's antenna rocking through an arc of 60 degrees at the
entrance to the Chesapeake Bay!

Tropospheric Ducting is a real problem with VHF-Marine. While Bruce has some
interesting stories to tell about making use of that up North, we normally
find it a real hindrance to good communications in the mid-Atlantic. Having
five or more CG Groups trying to answer the same mayday, and hearing traffic
from a hundred or more miles up and down the coast is not a good thing for
vhf-marine radio.

see http://home.cogeco.ca/~dxinfo/tropo.html for ducting forecasts

Jack Painter
Virginia Beach, Virginia