The Straits of Gibraltar is a perfect place to spot water mammals. The chances to see one of the three different species of dolphins (Common, Striped and Bottlenose) and pilot whales are very high when you take one of the whale watching tours. The possibility to spot a Killer Whale, a Sperm Whale or a Fin Whale is more limited. But you have to know that most of the companies that run the tourist boats belong to non-profit organizations, that will invest your money in protecting the endangered species.