Roughly thirty cetacean species have been recorded in Canarian waters, close to a third of every species known to science. Geology explains it. The seabed off the island's southern shore drops past 1,000 metres within three nautical miles of land, and the trade winds push nutrient-rich water along the same edge. Deep ocean therefore sits within sight of the beach umbrellas, which is why Dolphin Whale Watching Gran Canaria tours need so little sea room before the first dorsal fin appears. Puerto Rico was a fishing inlet with a handful of houses until the 1960s. The resort was drawn up as a planned development, its beach widened with imported sand, and its harbour, Puerto Base, dug out to hold pleasure craft rather than trawlers. The basin sits sheltered from the north-east trades by the bulk of the island, which made a year-round fleet possible where the windward coast could not. Commercial cetacean tourism reached the archipelago in the late 1980s and grew quickly enough that the Canarian government legislated: Decree 178/2000 set out how vessels may approach animals and created the yellow Barco Azul flag flown by accredited boats. Today Dolphin Whale Watching Gran Canaria tickets are issued for purpose-built catamarans rather than converted fishing hulls, and much of the local fleet has carried that flag for a quarter of a century. The animals themselves are largely resident. Short-finned pilot whales hold the channel between Gran Canaria and Tenerife year-round, moving in matrilineal pods that researchers track by dorsal-fin photo identification. Bottlenose dolphins work the same water. Atlantic spotted dolphins arrive in warmer months, often in groups of a hundred or more, and Bryde's whales, sperm whales and the elusive beaked whales pass through on deeper transits. Loggerhead turtles drift along the same drop-off, and Cory's shearwaters wheel above feeding groups in late summer. The Canary Islands rank among Europe's richest cetacean grounds for one reason: not migration, but permanence. The coast supplies the frame. West of the marina the cliffs of Mogán rise in ochre bands above Amadores, and the southern light turns the Atlantic a colour that photographs poorly and reads unmistakably in person. Poema del Mar, the aquarium opened in Las Palmas in 2017, gave the island a second, land-based way of reading the same ocean. Whale watching in Gran Canaria has become, in three decades, less an excursion than a defining feature of the island's south, and the Dolphin Whale Watching Gran Canaria fleet now feeds its sightings data into regional research programmes.