By Wayne Spivak, National Press Corps United States Coast Guard Auxiliary
Have you ever tried shouting across a small lake? Easy, isn’t it?
How about when you’ve been water-skiing, and try to get the attention of the towboat? Found it impossible, didn’t you???
Sound does and does not carry over water well. On calm lakes, bays, creeks, or in restricted visibility, sound carries exceptionally well. If you ever went camping around a lake, knowledgeable campers often would tell you to keep the noise down at night, since cool air, and a flat-water surface amplified the sound you were making, so that everyone on the lake heard you.
According to Howard Shaw, Ph. D. and Cheryl Jackson Hall, Ph. D., “Experience suggests that sound, like light, travels (more or less) in straight lines. However, to the contrary, sound actually tends to curve downwards over a lake’s surface.”
“Sound traveling along straight lines would disperse quickly into the space above the lake. Instead, sound that “should” rise up and be lost typically curves back down to the lake/ground level. Therefore, it sounds louder than it “should.” This is a well-known and easily demonstrated observation, measurable out there on real lakes.”