Luxury yacht, also known as a Superyacht or Megayacht, is a large and very expensive professionally-crewed sailing or motor yacht.
Super yacht generally refers to any yacht (sail or power) above 24 m (79 ft) and a Mega yacht generally refers to any yacht over 50 meters (164 ft.).
Luxury yacht smaller than 12 meters (39 ft.) is more commonly called a cabin cruiser or simply a cruiser.
Giga yacht is an extraordinary large luxury yacht, and first emerged as a hyperbolic term in the mid-2000s. As of 2012, yachts above 100 meters (330 ft.) are still rare but increasingly more common. They typically have five decks above the water line and one below. They incorporate many of the same features that smaller Mega yachts do, such as helicopter landing areas and swimming pools, though given their extra length, they also feature helicopter hangars and miniature submarines