Echo sounder

An echo sounder is a special tool that helps people who go on boats to figure out how deep the water is below the boat. The way it works is like this: the echo sounder sends out a sound wave (like when you yell "echo!" in a big room) that travels through the water and bounces back when it hits something. When the sound wave bounces back to the echo sounder, it measures how long it took for the sound to come back. The longer it takes, the deeper the water is. Think of it like a really cool game of Marco Polo, where the echo sounder is Marco and the sound wave is Polo! This helps people on boats know how deep the water is and can help them avoid running into things like rocks or shallow areas where they might get stuck. Pretty cool, right?