"Dan Krueger" wrote in message
ink.net...
The difference in four feet (assuming the same gain the the antennae) you
will only be able to communicate 1.18 miles further.

True, or close to it depending on the db gain you used. ;-)

Calculation for Range of an Antenna:

6db Antennas: Square Root of Height (in feet) above water x 1.15= Range in
miles
9db Antennas: Square Root of Height (in feet) above water x 1.52= Range in
miles

So we are talking a range of roughly 3 miles for the 4 foot vs 4.25 miles
for the 8 foot.

Not a big difference as you said.