Mirissa is one of very few places on earth where a blue whale is a half day trip from the beach. The continental shelf drops away only a few kilometres offshore, so the deep water that blue whales and sperm whales need sits within an hour or two of a fishing harbour, and the animals pass along it rather than being sought out across an ocean.
The season is the whole story. November to April is the south coast window, when the northeast monsoon leaves this side of the island calm. Outside it the whales and the workable sea move to the east, which is why so much disappointment here is a calendar problem rather than a luck problem.
Blue whale is the headline and is regular in season. Sperm whale is genuinely rare and comes in loose groups over deep water. What most trips actually deliver alongside them is dolphins: spinner dolphins bow riding on the run out, Indo-Pacific bottlenose offshore, and pantropical spotted and Risso’s in the deeper water. Bryde’s whale is regular and often in the same water as the blues. Killer whale and Omura’s whale are on this page because they are recorded here, not because you should expect them.
Highlights
Blue Whale
The largest animal that has ever lived, and off Sri Lanka a population that mostly does not migrate, which is why it can be seen almost year round. Where: The shelf edge a few kilometres offshore. Best: Nov-Apr, leaving port at first light.
Sperm Whale
The deepest diving mammal on earth, hunting squid two kilometres down, and occasionally gathering off Sri Lanka in pods of hundreds. Where: Deep water beyond the shelf edge. Best: Nov-Apr.
Bryde's Whale
A warm-water baleen whale that lunges up through bait balls with its mouth wide open. Where: Offshore, often in the same water as the blue whales. Best: November to April.
Spinner Dolphin
A small, slender dolphin that leaps clear of the sea and spins like a top in mid-air. Where: Bow riding on the run out to the whale grounds. Best: November to April.
Omura's Whale
Only described as a species in 2003, and not seen alive and confirmed in the wild until 2015. Where: Offshore water. Best: November to April.
Mammals
11 species
Spinner Dolphin Common
Stenella longirostris
A small, slender dolphin that leaps clear of the sea and spins like a top in mid-air.
Where: Bow riding on the run out to the whale grounds. Best: November to April. Often the first thing you see, and frequently in hundreds.
Blue Whale Regular Endangered
Balaenoptera musculus
The largest animal that has ever lived, and off Sri Lanka a population that mostly does not migrate, which is why it can be seen almost year round.
Where: The shelf edge a few kilometres offshore. Best: Nov-Apr, leaving port at first light. Deep water is a short boat ride from the beach, and the fleet is large in peak season.
Bryde's Whale Regular
Balaenoptera edeni
A warm-water baleen whale that lunges up through bait balls with its mouth wide open.
Where: Offshore, often in the same water as the blue whales. Best: November to April. The whale most often mistaken for a blue whale here. Three dorsal ridges on the head is the tell.
Indo-Pacific Bottlenose Dolphin Regular Near Threatened
Tursiops aduncus
The classic bottlenose of warm coasts, sociable, clever and quick to ride a bow wave.
Where: Offshore water on the whale watching route. Best: November to April.
Pantropical Spotted Dolphin Occasional
Stenella attenuata
Calves are born unspotted and acquire their speckling through life, so you can read a dolphin's age off its skin.
Where: Deeper water offshore. Best: November to April.
Risso's Dolphin Occasional
Grampus griseus
Old males are almost white, scarred head to tail by the teeth of other Risso's and the beaks of the squid they eat.
Where: Deep water beyond the shelf edge. Best: November to April. Older animals are so heavily scarred they look almost white.
Short-finned Pilot Whale Occasional
Globicephala macrorhynchus
Females go through menopause and live decades beyond breeding, one of only a handful of species on earth that do.
Where: Deep water offshore, usually in tight social groups. Best: November to April.
False Killer Whale Rare Near Threatened
Pseudorca crassidens
Has been recorded offering captured fish to divers and to other dolphins, apparently as a gift.
Where: Deep water offshore. Best: November to April.
Sperm Whale Rare Vulnerable
Physeter macrocephalus
The deepest diving mammal on earth, hunting squid two kilometres down, and occasionally gathering off Sri Lanka in pods of hundreds.
Where: Deep water beyond the shelf edge. Best: Nov-Apr. Secondary to blue whale here but a genuine possibility.
Killer Whale Very rare
Orcinus orca
The ocean's top predator, and off Sri Lanka they are known to hunt other whales, which is a thing very few people ever witness.
Where: Deep water off the shelf edge, occasionally alongside the blue whale boats. Best: December to April. An exceptional sighting even for the skippers who work this water daily.
Omura's Whale Very rare
Balaenoptera omurai
Only described as a species in 2003, and not seen alive and confirmed in the wild until 2015.
Where: Offshore water. Best: November to April. Only confirmed as a living species this century.
Reptiles
2 species
Saltwater Crocodile Regular
Crocodylus porosus
The largest living reptile and the ocean going giant of crocodiles, now virtually gone from Thai waters.
Where: The Nilwala River at Matara, upstream from the mouth, by boat. Best: December to April. Fifty to sixty animals in the surveyed reach, with a full range of age classes, so it is genuinely breeding.
Olive Ridley Turtle Occasional Vulnerable
Lepidochelys olivacea
The smallest and most numerous sea turtle, famous elsewhere for mass nestings of thousands at once.
Where: Offshore water on the whale watching route. Best: November to March. Often seen at the surface between whale sightings.
Sharks and rays
1 species
Whale Shark Rare Endangered
Rhincodon typus
The biggest fish in the ocean, a spotted, bus sized filter feeder and the undisputed holy grail of tropical diving.
Where: Blue water offshore. Best: November to April.
Planning
November to April, and boats leave around dawn because the sea builds through the morning. Take seasickness tablets before you board rather than after, because the run out to the shelf edge is long and open. The shelf drops close in here, which is why the blue whales come within range of a morning boat at all, and it is also why the run is rough. The fleet is large at the peak of the season.
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Frequently asked questions
When can you see blue whales at Mirissa?
November to April, when the northeast monsoon leaves the south coast calm. Outside that window the whale watching moves to the east coast around Trincomalee.
What are the chances of seeing a blue whale at Mirissa?
Good in season. The shelf edge sits close inshore and the animals are regular there through the window, though a blank day is always possible and any operator promising a sighting is overselling it.
What else can you see besides blue whales?
Spinner dolphins on almost every trip, Indo-Pacific bottlenose, pantropical spotted and Risso’s dolphins, short-finned pilot whales and Bryde’s whale. Sperm whale, false killer whale, killer whale and Omura’s whale are all recorded and all uncommon to rare.
How long is a whale watching trip from Mirissa?
Most run three to five hours from a dawn departure, because the boats have to reach the shelf edge and then work along it. The sea is calmest early, which is why they leave when they do.
Explore Sri Lanka wildlife by group
Mammals of Sri Lanka
Birds of Sri Lanka
Reptiles and amphibians of Sri Lanka
Fish of Sri Lanka
Sharks and rays of Sri Lanka
Reef invertebrates of Sri Lanka
Insects and spiders of Sri Lanka
Part of the Wildlife in Sri Lanka guide.
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Image credits
Square thumbnails are cropped from the original. Wide banner images are cropped to a band. Other images are resized only. No other changes have been made.
- Blue Whale: Carina Gsottbauer | CC BY-SA 4.0, cropped
- Sperm Whale: NOAA Photo Library | Public domain, cropped
- brydes-whale (resized): Chainfoto | CC BY 4.0, cropped
- Spinner Dolphin (cropped to square): Alexia Pihier for MDC SeaMarc Maldives | CC BY-SA 4.0, cropped
- Omura’s Whale (cropped to square): Salvatore Cerchio et al. / Royal Society Open Science | CC BY 4.0, cropped
- Bryde’s Whale (cropped to square): Chainfoto | CC BY 4.0, cropped
- Indo-Pacific Bottlenose Dolphin (cropped to square): Bernard DUPONT from FRANCE | CC BY-SA 2.0, cropped
- Pantropical Spotted Dolphin (cropped to square): NOAA Photo Library | Public domain, cropped
- Risso’s Dolphin (cropped to square): Lucy Keith-Diagne | CC BY 4.0, cropped
- Short-finned Pilot Whale (cropped to square): Adam U / NOAA/NMFS/Pacific Islands Fisheries Science Center Blog 2013 07 29 | Public domain, cropped
- False Killer Whale (cropped to square): Ricardo Fernandes | CC BY-SA 3.0, cropped
- Killer Whale: NOAA, United States National Oceanic and Atmospheric Administration | Public domain, cropped
- Saltwater Crocodile: Rutpratheep Nilpechr | Pexels Licence, cropped
- Olive Ridley Turtle (cropped to square): Bernard Gagnon | CC BY-SA 3.0, cropped
- Whale Shark (cropped to square): Jerome Paillet (IFREMER) | CC BY 4.0, cropped
- Purple-faced langur in the canopy: kanchana Amilani | Unsplash License, cropped
- White-throated kingfisher on a branch: kanchana Amilani | Unsplash License, cropped
- Green forest lizard in breeding colour: Anas Mohamed Nuski | Pexels Licence, cropped
- Bluestripe snapper over a reef: Jeffry Surianto | Pexels Licence, cropped
- Reef manta rays near the surface: Emma Li | Pexels Licence, cropped
- Nudibranch crossing the sea floor: Chris Spain | Pexels Licence, cropped
- Clipper butterfly on a leaf: Pixabay | Pexels Licence, cropped
Square thumbnails are cropped from the original. Wide banner images are cropped to a band. Other images are resized only. No other changes have been made.
- Blue Whale: Carina Gsottbauer | CC BY-SA 4.0, cropped
- Sperm Whale: NOAA Photo Library | Public domain, cropped
- brydes-whale (resized): Chainfoto | CC BY 4.0, cropped
- Spinner Dolphin (cropped to square): Alexia Pihier for MDC SeaMarc Maldives | CC BY-SA 4.0, cropped
- Omura’s Whale (cropped to square): Salvatore Cerchio et al. / Royal Society Open Science | CC BY 4.0, cropped
- Bryde’s Whale (cropped to square): Chainfoto | CC BY 4.0, cropped
- Indo-Pacific Bottlenose Dolphin (cropped to square): Bernard DUPONT from FRANCE | CC BY-SA 2.0, cropped
- Pantropical Spotted Dolphin (cropped to square): NOAA Photo Library | Public domain, cropped
- Risso’s Dolphin (cropped to square): Lucy Keith-Diagne | CC BY 4.0, cropped
- Short-finned Pilot Whale (cropped to square): Adam U / NOAA/NMFS/Pacific Islands Fisheries Science Center Blog 2013 07 29 | Public domain, cropped
- False Killer Whale (cropped to square): Ricardo Fernandes | CC BY-SA 3.0, cropped
- Killer Whale: NOAA, United States National Oceanic and Atmospheric Administration | Public domain, cropped
- Saltwater Crocodile: Rutpratheep Nilpechr | Pexels Licence, cropped
- Olive Ridley Turtle (cropped to square): Bernard Gagnon | CC BY-SA 3.0, cropped
- Whale Shark (cropped to square): Jerome Paillet (IFREMER) | CC BY 4.0, cropped
- Purple-faced langur in the canopy: kanchana Amilani | Unsplash License, cropped
- White-throated kingfisher on a branch: kanchana Amilani | Unsplash License, cropped
- Green forest lizard in breeding colour: Anas Mohamed Nuski | Pexels Licence, cropped
- Bluestripe snapper over a reef: Jeffry Surianto | Pexels Licence, cropped
- Reef manta rays near the surface: Emma Li | Pexels Licence, cropped
- Nudibranch crossing the sea floor: Chris Spain | Pexels Licence, cropped
- Clipper butterfly on a leaf: Pixabay | Pexels Licence, cropped