It's the Law: Specifically for Skiing

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

Wakeboarder being towed by a boat

Legal Requirements for Towing Skiers

It is illegal for vessels to tow person(s) on water skis, an aquaplane, or a similar device between one hour after sunset and one hour before sunrise.
Each person being towed behind a vessel on water skis or similar devices must wear a properly secured U.S. Coast Guard–approved Type I, II, III, or V PFD. Ski belts are not U.S. Coast Guard–approved. It is the legal responsibility of the owner of the towing vessel to enforce this requirement.
Every vessel (except personal watercraft) towing a person(s) on water skis or similar device must have:
A capable observer, other than the operator, 12 years of age or older or…
A wide-angle rearview mirror. The size of the mirror must be at least 78 square inches and have a field of vision of at least 170 degrees.
Every PWC towing a person(s) on water skis or a similar device must have mirrors mounted on both the right and left sides of the PWC (but not attached to the steering control) and the mirrors must be at least 2 ½ inches high by 4 inches wide.
The vessel operator must maintain reasonable distance from other vessels, people, and property to avoid endangering life or property. It is illegal to tow a person on water skis or similar devices behind your vessel, or to manipulate the water skis or similar devices, in a manner that causes the towed person to collide with another person or object.

Knowing proper hand signals will help the skier(s) communicate with their vessel operator or the observer.

Speed up	Slow down	Speed OK
Turn left	Turn right	Stop