Final answer:
Water skiers should use hand signals to communicate with the tow boat. These signals are an effective way to convey messages during water skiing activities.
Step-by-step explanation:
Water skiers should use hand signals to communicate with the tow boat. Hand signals are universally recognized gestures that can convey a variety of messages such as the desire to turn, slow down, speed up, or stop. They are the most effective and immediate way to communicate on water, as skiers may be at a distance where other methods like yelling may not work due to the noise of the boat and water. Unlike water skiing, if you're on the moon and your radio breaks, flashing a light would be the best way to communicate with a friend because sound cannot travel through the vacuum of space.