What must a person do before towing a person on water skis?

Before towing a person on water skis, it is crucial to ensure that the tow line is secure and the person being towed is ready. This step is essential for safety; a properly secured tow line prevents accidents or equipment failures during the tow, while confirming that the skier is ready ensures that they are prepared and alert, minimizing the risk of injury as they are being towed.

While other options, such as checking the weather conditions, ensuring all passengers are seated, and notifying other boaters in the area, contribute to overall boating safety, they do not specifically address the immediate actions required to safely commence towing a skier. The readiness of the tow line and the skier directly affects the safety of the activity, making it the most critical first step before beginning the tow.