"The United States Coast Guard (USCG) has officially classified stand up paddleboards (SUP) as a vessel. With the rapid growth of SUP in recent years on the West and East coast of the United States, the Coast Guard recently classified “paddleboards”, meaning SUP’s as “vessels.” SUP, the newly classified vessels must comply with federal Navigation Rules and “carriage” requirements when operated beyond the limits of a swimming, surfing or bathing area. Adult stand-up paddlers are required to have a USCG-approved life jacket also known as Personal Floatation Device (PFD, Type III) for each person, a sound signaling device (whistle), visual distress signal and navigation light (flashlight)."
http://worldpaddleassociation.com/20...ed-as-vessels/