What equipment is necessary when towing a water skier?

When towing a water skier, having either a mirror or an observer is essential for safety and ensuring proper monitoring of the skier. The observer's role is to keep a watchful eye on the skier's movements and any potential dangers, allowing the boat operator to focus on navigating. This dedicated attention is crucial for promptly responding to emergencies, such as if the skier falls or requires assistance.

A mirror can serve a similar function, giving the operator a better view of the skier without needing to divert attention from the path ahead. This equipment is necessary to comply with safety regulations and to help prevent accidents on the water. In contrast, the other options, while they might have their uses in boating, do not specifically address the critical safety aspects needed when engaging in water skiing activities.