A Nantucket sleighride was a term used by Nantucket whalemen to describe what occurs immediately following the harpooning of a whale. The whale, realizing it is harpooned, attempts to flee and thus drags a boat along with it. The speed of the "sleigh ride" would vary depending on the species of the whale, with certain species (e.g. humpbacks) giving faster rides. The sperm whale was the whale that caused the longest drag events, reaching speeds of 23 mph (37 km/h). The length of the drag for the sailors would last as long as the whale could swim before it became exhausted. Once the whale expended its energy, the sailors would kill it and harvest its oil.