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To add to the comments of Dan & Dave regarding radio waves: This analogy may help some understand what is going on.
Think of the radio frequencies in terms of wave fronts, like in a sine wave. Low frequencies have fewer wave fronts. High frequencies have a lot more wave fronts. When a wave front encounters resistance from substances such as water, it slows the wave front down. The higher the frequency, the more wave fronts, the more resistance it will encounter and the more it is slowed. The lower the frequency, the fewer wave fronts, the less resistance it will encounter and the less it is slowed.
Note: What is in the water also affects the amount of resistance it has: pure fresh water has the least resistance, chlorinated water has more resistance, salt water the most.
Thus the lower frequencies can penetrate more water before being stopped. It is the amount of water that can be penetrated that determines the usefulness of a frequency.
I used this analogy when I taught light theory and optics.
Now regarding 2.4 GHz, I talked to the owner of my local R/C hobby store (an avid R/Cer including boats) when 2.4 first came out. He observed that it had a tendency to reflect off water reducing receiver reception. In his experiments if the antenna is raised 18 inches above the water it did not have the reflection problem. He had some long replacement antennas made. I have purchased them and have used them on my surface ships.
Think of the radio frequencies in terms of wave fronts, like in a sine wave. Low frequencies have fewer wave fronts. High frequencies have a lot more wave fronts. When a wave front encounters resistance from substances such as water, it slows the wave front down. The higher the frequency, the more wave fronts, the more resistance it will encounter and the more it is slowed. The lower the frequency, the fewer wave fronts, the less resistance it will encounter and the less it is slowed.
Note: What is in the water also affects the amount of resistance it has: pure fresh water has the least resistance, chlorinated water has more resistance, salt water the most.
Thus the lower frequencies can penetrate more water before being stopped. It is the amount of water that can be penetrated that determines the usefulness of a frequency.
I used this analogy when I taught light theory and optics.
Now regarding 2.4 GHz, I talked to the owner of my local R/C hobby store (an avid R/Cer including boats) when 2.4 first came out. He observed that it had a tendency to reflect off water reducing receiver reception. In his experiments if the antenna is raised 18 inches above the water it did not have the reflection problem. He had some long replacement antennas made. I have purchased them and have used them on my surface ships.
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