Basking Shark
Cetorhinus maximus
Also known as: Bone Shark, Cape Basking Shark, Elephant Shark, Hoe-Mother, Sun-Fish
About This Species
Found in cool, productive coastal and oceanic waters, this filter-feeder spends much of its time cruising slowly near the surface in areas where zooplankton — particularly copepods — are densely concentrated. Watch for the distinctive sequence of dorsal fin, back, and crescent tail fin breaking the surface simultaneously as it moves in a slow, unhurried arc, and listen for the occasional audible splash as the enormous gape breaches slightly above the waterline. Late spring through midsummer offers the best chances in temperate inshore waters, particularly around headlands and tidal fronts on calm, sunny days when plankton blooms are visible as greenish surface discoloration and the flat sea allows fins to be spotted at distance.
Ethical Viewing Guidelines
- Maintain a minimum distance of 100 metres when in a vessel and avoid entering the water to swim or dive with individuals, as these animals are highly sensitive to approach and will sound (dive) if disturbed, disrupting vital surface feeding behaviour.
- In UK and Irish waters they are protected under the Wildlife and Countryside Act 1981, the Wildlife (Northern Ireland) Order 1985, and Ireland's Wildlife Acts, making it an offence to intentionally or recklessly disturb, injure, or kill them; similar protections apply across much of their range, including under EU Habitats Directive Annex IV.
- Reduce engine speed to under 6 knots well before reaching the minimum distance, never position a vessel in the animal's path, and if it approaches of its own accord hold position and cut the engine rather than manoeuvring around it.
Seasonal Activity
30,597 sightings · 2000–2026
Citizen science records via GBIF
Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Elasmobranchii
- Order
- Lamniformes
- Family
- Cetorhinidae
Photo
Wikimedia Commons / Wikimedia Commons
CC-BY-SA-4.0
Occurrence data from GBIF.