Orkney Marine Life: Seals, Whales, Dolphins & Orcas Guide

Few coastlines in Britain put you closer to wild marine mammals than Orkney. Twenty-three species have been recorded in these waters — grey seals on every skerry, harbour porpoises rolling through Scapa Flow, named orca pods that pass by on the way from Shetland to Iceland, and a winter pulse of humpbacks that nobody talks about enough. Here's where to look, when to look, and how to do it without disturbing what you came to see.

Orkney's Marine Mammal Residents and Visitors

Over twenty-three species of marine mammals have been recorded in Orkney waters, drawn by nutrient-rich currents and a constant supply of herring, sandeel and seal. The eight you're most likely to encounter:

• Grey Seal (Halichoerus grypus): Orkney is a global stronghold — roughly 10% of the world's grey seals breed here, and the islands produced about 22,150 pups in 2019 alone. Bulls reach 2.6 m, distinguished by the long 'Roman nose' profile and parallel nostrils. White-coated pups arrive between October and December.
• Common (Harbour) Seal (Phoca vitulina): Smaller (up to 1.85 m), dog-faced, V-shaped nostrils. Pups in June–July. Often seen at low tide hauled out in the unmistakable 'banana pose' — head and tail both lifted, belly slumped on the rock. Sadly, Orkney's common seals have collapsed by 85% since 1997 (8,500 down to roughly 1,300) and are still declining at around 10% per year.
• Harbour Porpoise (Phocoena phocoena): The smallest and most common cetacean. Year-round, peaks August–October. Look for the small triangular dorsal fin breaking the surface — Switha Sound regularly draws aggregations of 200+ animals in autumn.
• Risso's Dolphin (Grampus griseus): Robust, blunt-headed, and heavily white-scarred with age. Frequently sighted around Hoxa Head and outer Scapa Flow, peak July–September.
• White-beaked Dolphin (Lagenorhynchus albirostris): Larger and more energetic, often in big pods through summer, especially in Pentland Firth and offshore.
• Minke Whale (Balaenoptera acutorostrata): The most commonly sighted baleen whale, peak June–August on herring. Ferry crossings give you the best vantage.
• Orca (Killer Whale) (Orcinus orca): The apex predator. Sightings peak May–July; named pods including the 27s and 64s pass through regularly, often hunting seals close to shore.
• Humpback Whale (Megaptera novaeangliae): The under-publicised winter visitor — late autumn and early winter sightings have become near-annual in Scapa Flow and Pentland Firth since the WDC Shorewatch programme started recording the trend in 2020.

When to See What — Month by Month

One of the biggest mistakes visitors make is arriving expecting orcas in October or humpbacks in July. Each species has its window. Here's how the year breaks down across the eight species you're most likely to see:

If you're trying to maximise variety on a single trip, June and July are the strongest weeks of the year — orcas peak, minkes arrive, white-beaked pods turn up, and porpoises are everywhere. Late autumn (October–November) is the second sweet spot: peak grey-seal pupping, the porpoise aggregation in Switha Sound, and the start of the humpback season.

Best Places for Seal Spotting

Seals haul out all around Orkney's coast, but a handful of sites are reliable enough that you can build a half-day around them. Always observe from cliff-tops or paths — never approach.

Orkney sits at the heart of the selkie tradition — the seal-folk who shed their skins to walk on land. Spend half an hour watching common seals on a quiet shore and you understand exactly how the legend started.

Top Spots for Whale and Dolphin Watching

Cetacean sightings reward patience and elevation. The trick is to position yourself somewhere with a wide sea view, sit still for at least 30 minutes, and scan slowly through binoculars rather than chasing every splash.

• Coastal headlands: Marwick Head, Mull Head (Deerness), Hoxa Head, Yesnaby Cliffs, and Noup Head on Westray all offer big-sky sea views with elevation. Summer is best.
• Ferry crossings: The Pentland Firth runs (Pentland Ferries Gills Bay–St Margaret's Hope, NorthLink Scrabster–Stromness, Pentland Ferries Burwick–John o' Groats) are genuine cetacean hotspots. Pentland Ferries actively supports OMMRI's research, and crews often point out fins. Bring binoculars and stay on deck.
• Scapa Flow: Hoxa Sound, Switha Sound and the southern entrances regularly produce harbour porpoise, Risso's dolphin, and occasional minke. Read our Scapa Flow guide for context on the geography.
• Tidal races: Strong currents at the Pentland Firth, Eynhallow Sound and the Burra Sound concentrate prey and attract feeding cetaceans.

Orkney's Orcas: Pods, Names and Hunting Behaviour

Orkney is arguably the best place in the UK to see orcas. Three to four pods rotate through these waters between Iceland and Shetland, and the local research community knows almost all of them by sight.

• The 27s pod: Eight known individuals, led by matriarch Vaila with her 2022 calf. Members include adult males Hulk and Nótt, and the powerful male Úlfur. The pod ranges Shetland–Orkney–Faroes–Iceland and was photographed wave-washing seals at St Ninian's Isle in November 2024.
• Hunting behaviour: Orkney orcas specialise in seals — sometimes using sophisticated 'wave washing' to knock seals off skerries, sometimes simply ambushing them at known haul-outs. Sightings often happen within 50 m of shore.
• Identification: Each orca has a unique dorsal-fin shape and saddle-patch pattern. The Sea Watch Foundation, Hebridean Whale and Dolphin Trust and OMMRI maintain a UK photo-ID catalogue.

Beyond the 27s: other orca pods that visit Orkney

The 27s are the household name, but they're not the only family Orkney photo-ID catalogues recognise. Researchers track several distinct groups that rotate through these waters as part of the wider North Atlantic population — most spend the summer hunting seals around Shetland and Orkney, then move north to Iceland on the herring trail in winter:

• The 64s pod: a smaller family of three to five animals that has been logged repeatedly in Pentland Firth and along the north and east Mainland coast. The matriarch carries the catalogue ID 064; her offspring travel with her. They are often the pod responsible for inshore sightings near Mull Head and Marwick Head.
• The 19s pod: known for energetic surface activity and frequently seen breaching. Mid-summer is their window, usually pushing south through Westray Firth and along the west side of Mainland.
• The 65s pod: a more recent addition to the photo-ID record, often travelling in loose association with the 27s. Their visits are less predictable but consistently logged each season.
• Transients from further afield: animals from the Icelandic catalogue occasionally turn up off Orkney's outer islands. The first photographic confirmation of an Iceland–Orkney match was a milestone for the research community — it proved the connection that researchers had long suspected from prey movements alone.

If you see orcas, take photographs of the LEFT side of each dorsal fin (the saddle patch behind the fin is the diagnostic feature) and report them to OMMRI or the Orkney Cetacean Sightings Facebook group within 24 hours. Even a phone snap from a clifftop can match an animal in the catalogue and add a confirmed track point.

Basking Sharks: Orkney's Returning Giant

For decades basking sharks were almost a Western Isles speciality — the famous summer aggregations sat off Coll, Tiree and the Hebridean shelf. That story is changing. The Northern Isles, including Orkney, are now reliably on the basking-shark map between April and October, with peak sightings in July and August when surface plankton blooms run thickest.

Basking Shark Scotland — the country's dedicated research and tour operator — has formally added Orkney to its sightings catchment, and citizen reports through the Marine Conservation Society's Basking Shark Sightings Project now come in every summer from Pentland Firth, the outer Mainland headlands, and the waters off Westray and Papa Westray.

What you're looking for: the unmistakable triangular dorsal fin and the tip of the tail breaking the surface a couple of metres behind it, both moving slowly and in line. Basking sharks are surface filter-feeders, so on calm days you can see the conical mouth gaping wide just below the waterline as they cruise through plankton. They are the second-largest fish in the world — up to 10 m long, harmless to humans, and protected under the Wildlife and Countryside Act.

• When: April–October. Peak July–August on warm settled days after a stretch of southerly wind has driven plankton north.
• Where: Hoxa Head and the Pentland Firth from a calm-weather ferry are the most productive vantage points. Marwick Head and Mull Head are the most reliable from land. Hoy's west cliffs also produce occasional sightings.
• Report it: photos and GPS coordinates to the Marine Conservation Society or Basking Shark Scotland — the more verified records the further north the species range is officially mapped, which matters for designation of Marine Protected Areas.
• Code: the same 100 m rule applies as for cetaceans. If you are in a boat, stop the engine if a shark approaches, never chase, and never get in the water with one.

Harbour Porpoise and Minke: The Reliable Stars

If the orcas and basking sharks are the headliners, harbour porpoise and minke whales are the resident bands you'll always catch on tour. Set your expectations on these two species and you will not leave Orkney disappointed.

Harbour porpoise — the autumn aggregation in Switha Sound

The harbour porpoise is the smallest cetacean in British waters, rarely more than 1.7 m long, and easily missed unless you train your eye for the small triangular fin breaking the surface in a slow roll. They are present year-round across Orkney; the spectacle is what happens in late summer and autumn.

Switha Sound — the narrow channel between Switha and Flotta in southern Scapa Flow — produces tidal aggregations of 200 or more porpoises every August, September and October. Researchers think the animals are concentrating on schools of sprat and herring funnelled by the tidal race. The viewing window is roughly two hours either side of high tide on a calm day, watched from the road above Lyness or the eastern shore of Hoy.

Longhope Bay on the south coast of Hoy is OMMRI's main porpoise study site and a quieter alternative to Switha. Land-based watches there have recorded calves accompanying mothers from late June through September, which is the local calving signal.

Minke whale — the slow June arrival

The minke is the smallest and most numerous baleen whale in Scottish waters — sleek, dark-grey, about 7-9 m long, with a distinctive white band on the upper surface of each pectoral fin. Orkney's minkes arrive in June following the herring and sandeel run, and stay through August. They are the most likely large whale to show on a Pentland Firth ferry crossing.

Where they congregate: the tidal fronts at the western mouth of the Pentland Firth, the deeper water north of Westray and Papa Westray, and the strong flow at Eynhallow Sound between Mainland and Rousay. The classic minke surface pattern is a short, slightly rolling back-arch followed by a single dorsal fin appearance — no fluke usually shows on a normal dive. If you see fluke-up, you've almost certainly seen a humpback.

The best ferry crossings for minke are NorthLink Scrabster–Stromness on a flat-calm June morning, and the Tingwall–Rousay run on the same kind of day. Pentland Ferries' crews log their cetacean sightings to OMMRI and often share them with passengers as the boat is moving.

How to Contribute Sightings

Citizen-science reporting is genuinely valuable here — the local research community is small, and a single timestamped photo from a visitor can identify a known individual or confirm a previously-unrecorded movement. If you see something, report it:

• Orkney Cetacean Sightings (Facebook group): the fastest-moving channel, with locals and researchers active in real time.
• OMMRI — Orkney Marine Mammal Research Initiative: ommri.org accepts sighting reports and photos. They run dedicated porpoise studies in Longhope Bay on Hoy.
• Sea Watch Foundation: seawatchfoundation.org.uk runs UK-wide cetacean monitoring including the annual Orca Watch in late May.
• WDC Shorewatch: if you can spare a watch session at a designated site, the Shorewatch programme has logged over 100,000 watches and a million minutes of survey effort since 2005.

Always include date, time, exact location (lat/long if possible), number of animals, behaviour, and any photos or video — even poor-quality images can be diagnostic.

Decline, Strandings and Why It Matters

It's tempting to talk about Orkney's marine mammals only in superlatives. The full picture is more complicated, and worth a visitor knowing.

• Common seal collapse: the harbour seal population in the North Coast and Orkney Special Management Unit has fallen roughly 85% since 1997 and is still declining at about 10% per year, per the 2024 SCOS report. Cause uncertain — likely a combination of disease, prey shifts and possible orca predation pressure.
• Sanday strandings: on 11 July 2024, 77 long-finned pilot whales stranded at Tresness Beach, Sanday — the largest mass stranding in the UK in nearly a century. A second stranding of 23 pilot whales followed at Roo Beach in August 2025. Investigations continue.
• Grey seals are abundant; that doesn't mean the system is healthy. A booming top predator alongside a collapsing common seal population is a sign of an ecosystem in flux. Wildlife watching here is a privilege — treat it that way.

The Scottish Marine Wildlife Watching Code

Following the SMWWC isn't bureaucratic box-ticking — it directly affects whether the next visitor gets to see what you saw. The headlines:

• Maintain distance: at least 100 m from seals and cetaceans (300 m for whales with calves). Let the animals control the encounter.
• Be predictable: in a boat, no sudden speed or direction changes. Approach slowly from the side, never head-on.
• Limit viewing time: 15–20 minutes maximum per encounter to minimise stress.
• Don't crowd: max three boats around one group of animals.
• Never feed marine mammals.
• Extra caution during pupping seasons: Oct–Dec for greys, Jun–Jul for commons. Keep dogs on leads anywhere near haul-outs.
• No drones over haul-outs or pods. Drone disturbance is a NatureScot offence under the Conservation (Natural Habitats) Regulations.

Frequently Asked Questions

When is the best time to see Orcas in Orkney?

While orcas are recorded year-round, sightings peak between May and August — May, June and July are the strongest months as pods follow seal populations and migrate between Iceland, Shetland and Orkney.

Where is the best place to see seals?

St Mary's Village (Mainland) at low tide is the most reliable spot for common seals in classic banana pose. For grey seals, Widewall Bay (South Ronaldsay) and the Brough of Birsay skerries are dependable year-round, with peak numbers and pups Oct–Dec.

Do I need a boat trip to see whales or dolphins?

Not necessarily — many sightings happen from coastal headlands and ferries. That said, a small-group wildlife charter dramatically increases your chances of close-range porpoise, dolphin and seal encounters and offers a perspective you can't get from a clifftop.

How do I report a marine mammal sighting?

Post to the Orkney Cetacean Sightings Facebook group for fastest pickup, then submit to OMMRI (ommri.org) with the date, location, time, species, number of animals, behaviour and any photos. The Sea Watch Foundation also accepts UK-wide reports.

Are the animals dangerous?

Marine mammals are wild animals and should be treated with respect — never approach, touch or feed them. There is no record of orcas attacking humans in the wild anywhere in the world; the genuine risk is to the animals from human disturbance, not the other way around.

Choose accommodation with a sea view or near coastal paths and you can be watching from your kitchen window before breakfast — for many visitors that turns out to be the most memorable wildlife of the trip.