Dive Site: Hebrides, Scotland

They’re the second largest fish in the sea, and equally as impressive as their more famous cousins, whale sharks. And yet, basking sharks remain something of a mystery, an oddity that most people will only ever see on television, if at all.

Hebrides, Scotland may seem an unlikely place to encounter one of the ocean’s giants. But it’s nonetheless a perfect stop for those who want to find out just how magical basking sharks can be.

Basking sharks can reach lengths of over 33 feet/10 meters. As filter feeders, they must consume a huge amount of plankton to sustain their enormous size. It’s plankton that draws them to the Hebrides each spring. During this time, warming sea temperatures spark impressive blooms and nutrient upwellings, brought by seasonal ocean currents. These plankton blooms bring in their wake aggregations of up to 100 sharks. Their great dorsal fins cut swathes through the water as they feed along the sea’s surface. These feeding habits make the basking sharks easy to spot. Their fins sometimes protrude as much as six feet above the waterline.

Operators like Basking Shark Scotland offer guests the opportunity to observe these creatures in their natural environment. Snorkeling tours are designed specifically to find the sharks. Spotting basking sharks is not an exact science, though. Their movements change slightly each year depending on the location and timing of the plankton blooms. In 2014, Basking Shark Scotland enjoyed a 75 percent success rate for sightings throughout the season, which extends from May to September. The peak sighting period is between June and August. Guests and guides spotted up to 30 sharks at once in 2013, but boats have seen as many as 97 individuals together.

Maximize your chance of a face-to-face encounter with a basking shark by spending as much time as possible in their environment. To this end, Basking Shark Scotland offers dedicated tours that last as long as seven days. For time not spent in the water, there are a thousand other beautiful things to see, all of which combine to create the rich tapestry of life in the Hebrides.

Basking shark tours also offer the opportunity to see herds of red deer grazing along the coastline. Dolphins and whales also frequent these waters, and seal colonies bask in secret coves and inlets. When the boat spots a shark, the tour leader will establish whether guests can enter the water without impacting on its behavior. Once you’ve got the green light, a mask, snorkel, fins and an appropriately thick exposure suit are all you need.

The most common first impression of the basking shark is of its hugeness. Particularly of its vast mouth, which, with a width of approximately 3.3-feet/1 meter, is cavernous. Soon, however, you begin to notice other details — the slimness of the shark’s streamlined body behind its enormous mouth, the shocking redness that flashes between its gills in contrast with the mottled silver and brown of its wrinkled skin. You can clearly see the inside of its mouth. The white cage of its gill rakers glows palely through the teal green water.

The sharks are not aggressive, seemingly oblivious to the humans around them as they plough their way steadily through the soupy sea of plankton. Although the United Kingdom now protects them, this docile nature made them easy targets for the fishermen of the past. Today the IUCN still recognizes them as Endangered in the Northeast Atlantic. Those who search for them with Basking Shark Scotland can contribute to conservation efforts by helping with the company’s photo ID library and sightings record.

All encounters with the basking sharks occur on snorkel, but divers will find plenty of other underwater attractions in the Hebrides. The area offers wrecks, cold-water nudibranchs and plunging, productive wall diving. Basking Shark Scotland can also arrange those dives, as well as boat-based sightseeing for non-divers.