Tail sailing refers to the action of whales lifting their tails clear of the water for long periods of time.[1] The process is rarely observed by humans, and the precise motivation for this phenomenon is unknown.[2] It is thought that whales either undertake this activity to catch the wind and 'sail' through the water, or as a method to cool down. A third theory suggests that the whale is feeding close to the sea floor.
Scientists believe that tail-sailing is fairly common amongst certain species, such as the Southern right whale.[3]
Amazing siting by youtuber YBS Youngbloods