I am at the lifeguarding beach right now. Five miles from my beach is the town of Washburn. It is right accross the bay and some people think its Bayfield (some think its Canada). Yet for how far it is from here, I am connected to a WiFi hub at the Washburn Marina! Normally WiFi (the type of wireless internet most people use) is good for roughly 300 ft outside, and 100ft inside. The fact I can get their internet here from so far away is amazing, yet explainable.
Back where I went to school in Iowa, while waiting for the school bus, I could hear our band practice, even though school was about three miles away. What happens is there is warm air near the ground, then a layer of cool air on top. This temperature inversion bounces the sound waves like a sheet of glass, then off the ground until it got to me. This effect is well known for lakes and ponds, but also works under the water, and is a way to hide submarines. I remember a JAG episode in the first season where just this occurs...a sub needs to hide from another sub, so it goes deep enough that it hits a cold water inversion. The attacking sub’s sonar waves bounce off the inversion and can’t find the sub.
AM and Ham radio also do this with the inversion layers and other types of layers of the atmosphere. I remember meeting some Ham radio operators up here last year and they were talking about how during the Katrina disaster, they were able to talk to people in Louisiana and were able to contact family members for those in the disaster area. This was only possible with radio waves bouncing off the atmosphere and coming back down to earth.
WiFi is also a type of radio waves (2.4 GHz) and is reflecting off a cold layer here to give the same effect...communication from a crazy far distance!
Oh, great thing about the internet at the beach...Watching the sunset!
From the guy with his eye on the sky, Travis...the camping lifeguard
Edit: If my manager is reading this, Sara, I think each of our parks larger parks need this, free wifi for people to sit outside and work!