A superyacht or megayacht is a large and luxurious pleasure vessel. There are no official or agreed upon definitions for such yachts, but these terms are regularly used to describe professionally crewed motor or sailing yachts, ranging from 40 metres (130 ft) to more than 180 metres (590 ft) in length, and sometimes include yachts as small as 24 metres (79 ft).
Superyachts are often available for charter with a staff that caters to guests at a high standard of comfort. They may be designed to emphasize comfort, speed, or expedition capability. Depending on the season, superyachts may be most frequently found in the Mediterranean or the Caribbean. Many are available for charter at prices that exceed €100,000 per week. Larger examples may have more than one swimming pool; they may carry a variety of water toys, other boats, and some a helicopter.
At the beginning of the 20th century, when wealthy individuals constructed large private yachts for personal pleasure, some manufacturers, such as Cox & King and Charles L. Seabury and Company, were noted for their large steam yachts. The first half of the 20th century saw the first large motor yachts, including Charles Henry Fletcher's Jemima F. III (1908) at 34 metres (111 ft), Savarona (1931) at 136 metres (446 ft), and Christina O (1947 conversion) at 99 metres (325 ft).
The "Large Commercial Yacht Code (LY2)" of Great Britain and its dominions defines a "large yacht" as one that is 24 metres (79 ft) or more at the waterline and is in commercial use for sport or pleasure, while not carrying cargo or more than 12 passengers, and carrying a professional crew. The code regulates the equipping of such vessels, both at sea and in port—including such matters as crew duty times and the presence of a helicopter on board. The code has different levels of standard for vessels above and below 500 gross tons. Other countries have standards similar to LY2. Whereas yachts of 24 metres and below may be constructed of fiberglass, larger yachts are more likely to be constructed of steel, aluminum or composite fiber-reinforced plastic. Such yachts may be considered "superyachts" and are more commonly at 40 metres (130 ft) or more in length.
Whereas "commercial" large yachts may carry no more than 12 passengers, "private" yachts are solely for the pleasure of the owner and guests do not carry the passenger restriction. Yachts may be identified by flag—the country under which a yacht is registered. An industry publication categorizes superyachts by size, by speed, as "explorer" yachts, as sailing yachts, and classic yachts.
As of 2016, there were about 10,000 superyachts over 24 metres in length, worldwide. Of these about 80% were power yachts. The annual production rate was reported to be around 150. As of 2018, the 200 largest yachts ranged in length from 70 metres (230 ft) to 181 metres (594 ft)—the Azzam. The largest yacht by volume at 20,361 gross tons was Fulk Al Salamah. The largest sail-assisted motor yacht at 143 metres (469 ft) was Sailing Yacht A. As of 2018, the top 50 sailing yachts ranged in size from 53 metres (174 ft) to 107 metres (351 ft)—the Black Pearl. The 20 fastest superyachts ranged in speed from 50 knots (93 km/h) with 7,290-horsepower (5.44 MW) engines to 67 knots (124 km/h) with 20,600-horsepower (15.4 MW) engines for the motor yacht, World is not Enough.
Between 1998 and 2008, European production of superyachts grew by 228%, ending the period with a total production of 916 units and $10 billion in orders. In January 2020, Boat International listed 4,621 professionals connected to the superyacht industry since 1856, including 1,806 builders. The top ten builders were (shown with the total number of units built, since the founding of the company):
Each superyacht has a flag state where it is registered, but may have never visited. Common flag state registrars for large yachts are Cayman Islands, Marshall Islands, Isle of Man, and the British Virgin Islands, among others.
Superyachts typically frequent the Mediterranean Sea in summer and the Caribbean Sea in winter. Typical destinations in Spain and the French, Italian and Portuguese Rivieras include Cannes, Antibes, St. Tropez, Monte Carlo, Portofino, Porto Cervo, Cascais, Puerto Banús, Puerto Portals, and Palma, Majorca; explorer superyachts may cruise in remote areas worldwide.