Basking Shark

WiSe Accreditation in Cornwall

Basking Shark

At least 21 species of Sharks can be found in British waters with Blue, Shortfin Mako, Thresher and Porbeagle being among species either resident or seasonal to Cornish Shores.

However, it is the Basking Shark, the second largest fish in the world that Cornwall is famous for.

Basking Shark (Cetorhinus maximus)

It is a totally unforgettable experience to see a 10 metre giant with its mouth wide open swimming towards the boat...


In the summer time we have a lot of sightings of these creatures. They are easily spotted throughout the summer months as they feed close to the UK coast and close to the surface of the water. They are found in all the seas around the UK. Little is known about them in the winter, but as there aren't many (or any) sightings it has been suggested that they migrate offshore and to deeper water.


  • These creatures can grow to be almost the same size as a double decker bus - that's 15 metres long!
  • The large dorsal fin is easy to spot from a boat or the cliff top. On larger animals we often see it flopping to one side as the fin is too heavy to support itself upright out of the water.
  • Quite often the tail fin is seen above the water and the tip of the nose if it is feeding.


As the sea begins to warm up in May, the plankton blooms and this attracts the basking sharks. We see the plankton blooms from the boat, usually along tide lines where there are tiny bubbles on the surface. We hunt out these tide lines as they are often where the basking sharks are feeding. The sharks have 5 long gill slits on each side of their bodies and they have 'Gill Rakers', which sieve out the plankton from the sea water passing through them. The big sharks can filter the amount of water in an Olympic sized swimming pool in 1 hour!


Basking sharks are viviparous: this means the offspring develop inside eggs inside the womb, they hatch whilst still in the womb and continue developing, then the female gives birth to live young. The gestation period is though to be about 1 year although it could be as long as 2 to 3, with females giving birth in late summer.


The basking shark has been heavily hunted as unfortunately, it is an easy target. It is tolerant of boats and swims very slowly when feeding at the surface. It was mainly hunted for its liver oil, meat and fins. They have been hunted almost to extinction in many parts of the world, but the majority of fisheries are now closed. Tragically however, they are still hunted in Asia for their fins to be used in the infamous shark fin soup.

In the EU they are a prohibited species, meaning it is illegal to catch them in EU waters. They are also protected against harassment and disturbance from boats in British waters under the Wildlife and Countryside Act (1981). At Orca Sea Safaris, we are WiSe accredited, which means we have been trained in how to approach marine wildlife safely in a boat, how to minimise disturbance caused by our boat, and how to recognise distressed behaviour.

"As I scanned the bay in front of us, wishing and hoping to see a black fin in the brilliant blue water, I literally held my breath as I saw what I'd been searching for - a basking shark fin slicing through the water. I jumped up from my seat and couldn't stop myself from shouting 'Fin! Fin!' As we drew closer I burst into tears, I was so excited and completely overwhelmed by it's beauty. Then I had to try and string a sentence together to tell the passengers some information about them!" My first basking shark. Laura, crew Orca Sea Safaris.

Wildlife in Cornwall

Cornwall's warm climate and diverse marine life is all due to the Gulf Stream.

It brings warm water flowing from the South up through the Atlantic Ocean past Cornwall, which then mixes with cooler Northern waters.
Species spotted are increasing constantly as more people join our Sea Safari expeditions and as sea temperatures rise we are seeing an increasingly diverse range of marine wildlife on our boat trips.

WiSe Accredited

Prioritising the safety & wellbeing of our resident wildlife is very important to us. Our skippers adhere to strict guidelines provided by the WiSe Foundation and other conservation groups. Read about our Code of Conduct and Eco Tourism here.