When towing one person behind a vessel what must you have on board?

When towing one person behind a vessel, you must have a competent observer on board who is at least 12 years old, in addition to the operator. The vessel must also be equipped with proper safety gear, including life jackets for the person being towed and a means of communication, such as a whistle or horn, to signal for help if needed. Additionally, you should ensure that the towing equipment, such as a tow rope, is strong and suitable for the activity.