• Rachael Bentley

SWIMMING WITH BASKING SHARKS

From June to September these gentle giants pay our coastlines a visit. I headed for the isle of coll to take a dip.



On my trip to Penzance last year, I didn’t see any basking sharks, so to up the odds a bit this time, I set off for Scotland. I left home in a balmy 25 degrees, yet arrived to ten degrees, gale force weather warnings and a big storm. Not great news for shark hunting. But I made it to Coll, where I met the guys from Basking Shark Scotland. It was great to meet people so passionate about these giant fish and learn a bit more about the sharks before hopefully, getting in the water with them.


7 basking shark facts


Basking sharks can grow up to 10m long. The ones seen around Coll range from 5-8meters, that’s 25ft!

They are the second largest fish on Earth. Only the Whale shark is larger.

Their mouths are over a meter wide.

They don’t have big teeth. I wouldn’t be so eager to hop in with them if they did. They have tiny teeth and filter seawater using gill rakers, fueling their huge bodies on a diet of plankton soup.

They eat Zooplankton.

These are small organisms, each about the size of a pinhead. They look like pink floating dots close-up. Zooplankton are weak swimmers and drift in their millions in ‘blooms’ or nutrient-rich streams, where warm and cold waters meet. Luckily Coll is a real hotspot. These blooms were something we’d be looking for – resembling dark water slicks on a calm sea.

Basking sharks have two penises!!!

I know, weird… I know, because I got up-close and personal. At first I thought I’d seen two lampreys (fish that feed off the sharks like vampires), only to be told by our guide that they were penises (or rather two grooved organs called claspers). If the male shark happens to dock along the right side of the receptive female, he uses his left clasper and visa versa.

If you see one, there may be more.

Shane, our trusty skipper and shark expert, told us that when the plankton streams are narrow and deep sharks can swim stacked five high, happily cruising their soup trail. Sharks can follow other sharks too, often being mistaken for even bigger creatures.


Basking sharks are huge and yet there’s still a surprising amount we don’t know about them. A small-scale tagging project showed individuals travelling to Newfoundland and others heading for the Med, we don’t know much about where they breed and it is suspected that in the winter they head for deep water plankton but some expects think they may even go dormant, hardly feeding.


“Over three days we searched the seas around Coll for a tell-tale, jaws-like fin rising from the waters.”


Once you find a shark…

The most important thing to remember, is not to chase the sharks or interrupt their natural behaviour. Shane positioned the boat well ahead of a large male, in the hope that he would swim towards us on its feeding path. They can sense us using water pressure, so we would need to stay calm and not splash about, otherwise we could divert them from their feeding paths.


As we entered the water, the shark we’d seen looked a long way off. We swam closer and waited. I was quite nervous. Then suddenly, from the murk appeared a white mouth, which grew larger and clearer as the shark came closer. We saw it feed, then close its mouth and filter its haul, before opening wide for more. Actually it wasn’t that scary, they seem only to care about plankton.


A large male headed on a collision course with me, like a four-by-four driver not caring about a tiny vehicle. I tried to get out of its way. He simply glided a little lower, passing right beneath me. I could see its mottled skin, like a plane tree and was stunned when his tail flicked past and he disappeared back into the haze of food.

I had a freezing cold, wet day, spent feeling a bit sea sick – but it was worth every soggy minute, for an experience I won’t forget in a hurry.

Where to see basking sharks: The West is best, Head for the Hebrides (Coll, Skye, Mull), Isle of Man, Malin Head and South-west England (Devon, Cornwall, Scilly).

The Isle of Coll (I-love-coll)

The sun showed its face briefly during my stay, so I took the opportunity to take a look around the island. Coll is thirteen miles long, rugged and wild with the winds keeping trees at bay. But it’s also stunning, peaceful and has crystal clear, turquoise seas – especially around the seal lagoon at the north of the island.



There is only one hotel/restaurant in Arinagour and two tiny shops for provisions, which aren’t open every day, so come prepared.



If you’re lucky, you could see Otters near the jetty, or a Sea Eagle overhead. Head out on the water and as well as sharks there are Dolphins, Sunfish or even a passing Orca! The news that a killer whale had been seen two days previously made me slightly nervous about hopping into the water dressed like a seal.



We were so lucky on our trip, even with the bad weather we still saw more than half a dozen sharks, Harbour Porpoise and a small Minke Whale. Thanks, to the guys from Basking Shark Scotland and the rest of my group for all being so lovely and making it such a brilliant few days.