In article , rickman
wrote:

A 3 foot high antenna and a 200 foot high antenna
give nearly 20 statute miles of range. Will 5 watts be heard that far
away?

Rick-

I have not done the calculations, but think your limit is line-of-sight
rather than power. I once talked 50 miles to an aircraft on Two Meters,
using a 1 watt handheld with rubber ducky antenna.

This assumes the Coast Guard does not have their squelch set too tight.

Fred