The Law
The law requires boats to be equipped with an approved PFD or lifejacket of an appropriate size for each person on board (except for any infant who weighs less than 9 kg or any person whose chest size exceeds 140 cm). In order for an inflatable PFD to meet this requirement, it must be: worn while in an open boat, or worn while on deck or in the cockpit or be readily available to persons below deck of vessels with cabins.
A PWC rider, white-water paddlers or if the person is less than 16 years of age and weighs less than 36.3 kg, may not wear inflatable PFD's. Sail boarders may not wear the automatically inflatable type.
Information provided by the North American Safe Boating Campaign.