query: subclass_of freeline skates
supports: Freeline skates are a pair of skates designed to give the feeling of skateboarding , snowboarding , surfing , and inline skates all in one . They consist of two separate metal or wooden plates with two wheels attached by a form of `` truck '' designed specifically for the skates . The technique used to skate with Freelines is unique to the skates , and is a challenging wave - like motion . The individual skates , when ridden together , produce speed , agility , and natural self - propulsion , allowing for uphill motion . Inline skates are a type of roller skate used for inline skating. Unlike quad skates, which have two front and two rear wheels, inline skates typically have two to five wheels arranged in a single line. Some, especially those for recreation, have a rubber "stop" or "brake" block attached to rear of the frame. A tidal bore, often simply given as bore in context, is a tidal phenomenon in which the leading edge of the incoming tide forms a wave (or waves) of water that travels up a river or narrow bay against the direction of the river or bay's current. A skateboard is a type of sports equipment used primarily for the activity of skateboarding. It usually consists of a specially designed maplewood board combined with a polyurethane coating used for making smoother slides and stronger durability. Most skateboards are made with 7 plies of this wood. Inline skating is a sport practiced widely internationally. Inline skates typically have 2 to 5 polyurethane wheels, arranged in a single line, although 5 wheel designs are no longer manufactured. The in-line design allows for greater speed than roller skates and better maneuverability. The in-line wheels are coupled with boots designed for skating over and around various obstacles. Inline-skating is practiced and performed using inline skates designed for race tracks, skate parks, Urban areas, and off-road. Snowboarding is a recreational activity and Olympic and Paralympic sport that involves descending a snow-covered slope while standing on a snowboard attached to a rider's feet. Skateboarding is an action sport which involves riding and performing tricks using a skateboard. Skateboarding can also be considered a recreational activity, an art form, a job, or a method of transportation. Skateboarding has been shaped and influenced by many skateboarders throughout the years. A 2009 report found that the skateboarding market is worth an estimated $4.8 billion in annual revenue with 11.08 million active skateboarders in the world. In 2016, it was announced that skateboarding will be represented at the 2020 Olympic Games in Tokyo, Japan. Snowboards are boards that are usually the width of one's foot longways, with the ability to glide on snow. Snowboards are differentiated from monoskis by the stance of the user. In monoskiing, the user stands with feet inline with direction of travel (facing tip of monoski/downhill) (parallel to long axis of board), whereas in snowboarding, users stand with feet transverse (more or less) to the longitude of the board. Users of such equipment may be referred to as "snowboarder"s. "Commercial snowboards" generally require extra equipment such as bindings and special boots which help secure both feet of a snowboarder, who generally rides in an upright position. These types of boards are commonly used by people at ski hills or resorts for leisure, entertainment, and competitive purposes in the activity called snowboarding. Surfing is a surface water sport in which the wave rider, referred to as a surfer, rides on the forward or deep face of a moving wave, which is usually carrying the surfer towards the shore. Waves suitable for surfing are primarily found in the ocean, but can also be found in lakes or in rivers in the form of a standing wave or tidal bore. However, surfers can also utilize artificial waves such as those from boat wakes and the waves created in artificial wave pools. A wave pool is a swimming pool in which there are artificially generated, reasonably large waves, similar to those of the ocean. Wave pools are often a major feature of water parks. Siam Park City Water Park in Thailand is home to the world's largest wave pool certified by Guinness World Records, and Siam Park (Tenerife) in Spain is home to the biggest man made waves (about 3 meters (9.8 ft)) in the world. In physics, a standing wave  also known as a stationary wave  is a wave in a medium in which each point on the axis of the wave has an associated constant amplitude. The locations at which the amplitude is minimum are called nodes, and the locations where the amplitude is maximum are called antinodes. An ocean (the sea of classical antiquity) is a body of saline water that composes much of a planet's hydrosphere. On Earth, an ocean is one of the major conventional divisions of the World Ocean, which covers almost 71% of its surface. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern (Antarctic), and Arctic Oceans. The word "sea" is often used interchangeably with "ocean" in American English but, strictly speaking, a sea is a body of saline water (generally a division of the world ocean) partly or fully enclosed by land.
candidates: ability action activity art boat brake city edge english line man market method ocean park phenomenon physics planet point recreation river road roller sea single skating speed sport sports equipment stance standing wave surface swimming swimming pool travel type user water water park wave wood
answer: sports equipment