Basking sharks (Cetorhinus maximus) are are gentle, slow-moving fish that pose no threat to humans. Basking sharks are filter feeders, swimming slowly near the surface with their mouths open to strain plankton, copepods and fish larvae from the water. They use specialised gill rakers to trap food before swallowing, and a single shark can filter thousands of litres of seawater each hour.
In terms of size, basking sharks are the second-largest fish on Earth, surpassed only by the whale shark. Adults typically measure between 6 and 8 metres in length, though exceptional individuals may grow even larger. They can weigh over 2 tonnes, with enormous bodies supported by a distinctive triangular dorsal fin and a crescent-shaped tail that helps propel them through the water. Their most striking feature is their vast mouth, which can open nearly a metre wide. They can live until they are 50 years old.
When to see Basking Sharks in Pembrokeshire
In Pembrokeshire and surrounding Welsh waters you can see them between May and September, sometimes stretching into late October in good years. During this period the water warms, plankton blooms, and sharks move into coastal areas — making summer the best time to see them. Around St Brides Bay and St Davids trough to Strumble head are some of the best places to see Basking Sharks during those summer months. Look out for the triangular dorsal fin that can be as much as a meter long.
There are many local boat trips that will give you a good chance of seeing Basking Sharks, so why not book a stay at Galwad y Mor for a chance of seeing an ocean giant.
N.B. Basking sharks are a protected species in UK waters, and there’s a strong emphasis on observing them responsibly. If you’re on a boat, stay at least 100 m away and follow guidance from your operator or local marine codes of conduct to minimise disturbance.
