Range of a portable vhf

[Pedro]

Since replacing my antennae and fishing the new one through the Gunnel wire bundle seems to be a winter project I need to know how far a portable vhf reaches?

[DougSea]

See this write up for a good, practical explanation of VHF range.

http://www.boatingmag.com/marine-vhf-radio-range

Bottom line - approx. 3 miles to another hand-held. Further to a shore station (like the CG) with a tall antenna. Power adds clarity but not as much range. That comes from antenna height.

[Gypsyjon]

VHF radios, whether Marine of Ham 2 meter are line of sight. Thus the higher you get the antenna the further you can broadcast and receive. So you can hit the horizon and maybe just a bit further since VHF radio waves will curve over the horizon just a tiny bit. VHF is pretty much all about the antenna, not so much the power.

Ham radio VHF's use repeaters normally located on the tops of tall buildings or mountains to gain range. I do not think that marine VHF repeaters exist, maybe the Coast Guard has some though.