I've been an amateur radio operator for 23 years. I also got my start as a chief engineer for an AM/FM radio station in 1987, and have been a television engineer since 1996. I don't think that some wikipedia quoting know-nothing is going to "school" me on the propogation of radio waves. Tropospheric ducting is exactly what allowed every person that has talked well over 60 miles between two boats to do so. Guess where these ducts are most active? Coastal regions. VHF signals bounce off more than just inversions, too. While the higher VHF band is less likely to be able to bounce off the ionosphere, it does indeed happen during high sunspot activity. As a matter of fact, while driving in to work this morning, I was conversing from central NC to a UHF repeater located in New Jersey. If the UHF signal is propogating that far, for sure VHF was loud & strong all morning long.
Again, you prove that you know nothing about what you speak. You are also skipping past what I quoted you as saying, which is that you claim VHF does not go around trees or river bends.
Since you like interwebs sites to prove your point, take a look at this site.
http://aprs.mountainlake.k12.mn.us/Right now I see that there's a great amount of ducting activity going from the Baja area all the way up to a hundred miles or so North of Sacramento. How can that be? I guess in your physics world, these people that communicate over 700 miles, right now at 2:32pm EDT on August 19, 2014, on the 2 meter amateur radio band (just 20 MHz or so lower than the VHF marine band) are doing one of two things; lying or lying. Instead, in your world, people can't even communicate 4 miles if there are any trees around.
You're what we amateur radio operators know as "the guy that needs to swap out his PTT button for an RTL button"*.
Referring to my Reference Data for Radio Engineers, Fourth edition, I see that a base station antenna located 160' up a tower sitting in the yard of a marina located say, 20' above the shoreline (180' AMSL) will be able to "see" line-of-sight stations with an antenna using your hypothetical height of 30' above water gives a maximum of ~23 miles. So, how is it that we can communicate a greater distance? Well, the easiest way to explain that is that the visual horizon and the "radio horizon" is different. The lower the frequency, the more the radio signal "bends". One other important factor your interwebs don't mention (I assume -- I didn't even bother to read them): a mode of propogation called "tropospheric scatter". Tropo scatter is the scattering of a signal caused by moisture in the atmosphere; yet another thing that is common in coastal areas. The signal effectively bounces off the moisture located in the column of air between two points. Use a sensitive and efficient narrow-band signal such as the 15FE signal used by VHF marine, a decent high-gain antenna, and the moderate power that marine radios use, and it's quite feasible to go 75 miles even with just tropo scatter. One thing for you to Google, since that seems to be the only way you amass knowledge, would be "Distance from Florida to Cuba" and then "Cuban tropo scatter station". While you're at it, you might want to Google something like "Why was my high school physics teacher so wrong about what happens in the real world?"
Oops - I seem to forget that fact that you think reading a wikipedia article for 15 minutes will let you get to know a subject much better than someone who has 27 years experience in the matter.
*PTT = Push To Talk. RTL = Release To Listen.
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