Cetacean surfacing behaviour is a group of unique behaviours demonstrated by the Cetacea order when they come to the water's surface to breathe. Time intervals between surfacing can vary depending on the species, surfacing style or the purpose of the dive, and some species have been known to dive for up to 85 minutes at a time when hunting. In addition to respiration, cetaceans have developed and use surface behaviours for many other functions such as display, feeding and communication. All regularly observed members of the order Cetacea, including whales, dolphins and porpoises, show a range of surfacing behaviours. Cetacea is usually split into two suborders, Odontoceti and Mysticeti, based on the presence of teeth or baleen plates in adults respectively. However, for the purpose of this article Cetacea will be split into whales (large (> 10 m) sized cetaceans such as sperm and most baleen whales) and dolphins and porpoises (all medium and small sized (< 10 m) Odontocetes including orca) as many behaviours are correlated with size. Although some behaviours such as spyhopping, logging and lobtailing occur in both groups, others such as bow riding or peduncle throws are exclusive to one or the other. It is these energetic behaviours that humans observe most frequently and are generally most fascinated with, which has resulted in a large amount of scientific literature on the subject and a popular tourism industry.