What IS a Yacht?
Twenty years ago a 75-foot vessel was considered large and a 100-foot vessel was rare. Today 100-footers are common and some private vessels are mammoths-- Microsoft founder Paul Allen’s Octopus is 410 feet and Platinum, a new (2005) vessel owned by an Arab sheikh is the world’s largest yacht at 520 feet.
The term "yacht" comes from the Dutch "jot," meaning "hunt" and referring to a fast sailing vessel used to hunt pirates. There has never been agreement on what constitutes a “yacht.” The California Department of Motor Vehicles, responsible for registering boats, defines a yacht as a vessel of 16 feet or more in length designed to be propelled by sail or power. The U.S. Coast Guard, a more authoritative source, defines a yacht as a vessel over 26 feet in length. Today, many would think these definitions ludicrous, especially in light of the recent increases in vessel size.
Perhaps the most useful definition has nothing to do with size. Rather, it focuses on function:
A yacht is a sail- or power-driven vessel, usually private though state vessels might be included, that is used
for pleasure and is designed for overnight or long-distance use. As such, it typically has sleeping space (berths or
staterooms), cooking space (a galley), and "necessary" space (heads).
This definition allows a vessel of almost any size to be called a yacht. But because we yearn for a more finely graded definition, we have a proliferation of yachtness terms: one hears of “pocket yachts,” “yachts,” “super yachts,” “mega yachts,” and even “mega-mega yachts.”
Research suggests that the primary division is between yachts and super yachts: A super yacht is generally defined as a yacht with overall length exceeding 24 meters (79 feet); this definition is found in a number of sources, including http://en.wikipedia.org/wiki/Yacht. The terms mega yacht and super yacht are often treated as synonyms--once the vessel reaches 80 feet there are no further formal gradations of yachtness--but the wikipedia reference to "yacht" defines superyachts as longer than 79 feet and megayachts as longer than 164 feet. According to this taxonomy, Myeerah, at 90 feet, is a small super yacht while Octopus and Platinum are extremely large megayachts.