It's the Law: Specifically for Skiing

Vessel operators towing a person(s) on water skis or a similar device have additional laws they must follow.

Towing Skiers

• Every vessel towing a person(s) on water skis, an aquaplane, or other device must have on board, in addition to the operator, an observer at least 12 years old and in a position to observe the progress of the person(s) being towed. Boats equipped with a wide-angle, convex, marine rear-view mirror in a position to observe the skiers being towed are exempt from this requirement; however, PWC operators may not substitute a mirror for an observer (that is, a PWC must have an observer at least 12 years old).
• All persons being towed behind a motorboat or motorized device on water skis, an aquaplane, or other device must wear a USCG-approved PFD (life jacket).
• It is illegal for vessels to tow a person(s) on water skis, an aquaplane, or other device between one-half hour after sunset and one-half hour before sunrise. This restriction does not apply to night water-skiing or aquaplaning on controlled areas designated for those purposes where adequate lighting is provided.
• It is illegal to operate or manipulate any towing vessel, a tow rope, or other device in such a way as to cause the towed device or towed person(s) to collide with or strike any object or person(s).
• If towing a person on skis or other device with a PWC, the PWC must be rated to carry at least three people—the operator, the observer, and the retrieved skier.