What must be displayed when towing a person on water skis?

When towing a person on water skis, displaying a bright orange flag is a critical safety measure. This flag serves as a visual alert to other boaters and those in the vicinity, indicating that someone is in the water being towed. The bright color is chosen for its high visibility, making it easier to identify from a distance and in various weather conditions. It helps ensure that other boats maintain a safe distance from the area where the skier is being towed, thus reducing the risk of accidents.

The other options, while they may pertain to safety equipment in boating, do not specifically fulfill the requirement for signaling that a person is being towed. For example, safety vests and life jackets are essential for the safety of the skier but do not provide an indication to other boaters about the tow situation. A warning light is typically used for visibility at night or in low-light conditions but is not a universal requirement for water skiing. Using a bright orange flag effectively communicates the active tow situation to promote safety on the water.