Whale watching is the practice of observing whales and dolphins (cetaceans) in their natural habitat. Whale watching is mostly a recreational activity (cf. birdwatching), but it can also serve scientific and/or educational purposes. A study prepared for IFAW in 2009 estimated that 13 million people went whale watching globally in 2008. Whale watching generates $2.1 billion per annum in tourism revenue worldwide, employing around 13,000 workers. The size and rapid growth of the industry has led to complex and continuing debates with the whaling industry about the best use of whales as a natural resource.
Organized whale watching dates back to 1950 when the Cabrillo National Monument in San Diego was declared a public venue for observing Gray Whales and the spectacle attracted 10,000 visitors in its first year. In 1955 the first water-based whale watching commenced in the same area, charging customers $1 per trip to view the whales at closer quarters. The industry spread throughout the western coast of the United States over the following decade.
In 1971 the Montreal Zoological Society commenced the first commercial whale watching activity on the eastern side of North America, offering trips in the St. Lawrence River to view Fin and Beluga Whales.
In 1984, Erich Hoyt published the first comprehensive book on whale watching, The Whale Watcher's Handbook which Mark Carwardine called his number one "natural classic" book in BBC Wildlife Magazine.
By 1985 more visitors watched whales from New England than California. The rapid growth in this area has been attributed to the relatively dense population of Humpback Whales, whose acrobatic behavior such as breaching (jumping out of the water) and tail-slapping thrilled observers, and the close proximity of whale populations to the large cities there.