A giant oceanic manta seen from below

Revillagigedo National Park · Mexico

Giant mantas that come to you.

A field guide to the mantas, sharks, whales, dolphins, fish and birds of the Revillagigedo Islands, with where and when to look for each and links to go deeper.

Meet the mantasWhales and dolphins

Photo Megan Applegate (Socorro)

366+fish species, 26 found nowhere else (Pew 2018)
37species of sharks and rays (Pew 2018)
2,000humpback whales visit, at most (UNESCO)
148,087 km²closed to fishing since 2017 (Pew 2018)

Why Socorro

The Revillagigedo Islands are four volcanic islands, Socorro, San Benedicto, Roca Partida and Clarión, about 386 km southwest of the tip of Baja California (UNESCO). They became a UNESCO World Heritage Site in 2016 (UNESCO), and in 2017 Mexico closed 148,087 km² around them to fishing, its largest fully protected marine reserve (Pew 2018).

Divers come for some of the largest gatherings of giant oceanic mantas known (UNESCO), which come close to divers at the cleaning stations, for sharks, and for humpback whales and bottlenose dolphins (Divernet). The islands are reached only by liveaboard, about 24 hours from Cabo San Lucas, between November and May. Currents can be strong and seas rough; the diving suits experienced divers (Divernet; Scuba Diving).

Location

Where the sites are

The sites named under “What divers report”, spread over three islands up to about 130 km apart.

Dive sites in the islands

SOCORROSan BenedictoRoca Partida1. The Boiler, San Benedicto12. The Canyon, San Benedicto23. Roca Partida34. Roca O’Neal, Socorro45. Punta Tosca, Socorro56. Cabo Pearce, Socorro620 km

Dive sites, from north to south

  1. 1The Boiler, San Benedicto
  2. 2The Canyon, San Benedicto
  3. 3Roca Partida
  4. 4Roca O’Neal, Socorro
  5. 5Punta Tosca, Socorro
  6. 6Cabo Pearce, Socorro

The site map works offline and prints. Satellite is interactive: zoom and drag, and tap or hover a pin for its name (it needs an internet connection). Positions are approximate. The Boiler and The Canyon are both off San Benedicto, but their exact positions are not published, so both pins point to the island. Other positions: NGA GeoNames. Coastline © OpenStreetMap contributors.

Choose your dive

Seven field pages, with where and when to look for each species and links to go deeper.

Giant oceanic mantaMantasThe giant oceanic mantasColour forms, the population, where to see them and how to behave.Whitetip reef sharkSharksEight sharksWhere and when to see each, and the marks that tell them apart.Galápagos sharkShark IDTell the grey sharks apartCommon bottlenose dolphinMammalsHumpbacks, dolphins and orcasPacific creolefishFish18 reef fish, with the Clarion angelfishNazca boobyBirdsLand birds found nowhere else, and the seabirdsLandVolcanoes, endemic reptiles and restoration

When the big animals come

Pick a month to see which big animals are at their peak. Liveaboards run November to May (Bluewater Dive Travel). The water is warmest, about 24–27 °C, in November, December and May, and coolest, about 21–23 °C, from January to April (Bluewater Dive Travel). Check season and conditions with your operator before booking.

Peak Jan–Apr

Humpback whale

January to early April, to calve and train their young (DAN); song is most often heard on dives in February and March (Bluewater Dive Travel).

Whale shark
Peak Nov–Dec

Whale shark

Most common in November and December, according to one operator (Bluewater Dive Travel); another account gives April and May (DAN).

Bait balls
Peak Late Apr–May

Bait balls

Bait-ball season starts in late April, with sharks and tuna hunting the schools (Bluewater Dive Travel); silky sharks are far more numerous in spring (DAN).

Photo Megan Applegate (Socorro)

Six to know by sight

The manta and the sharks most often reported here, with the mark that gives each away. The Mantas and Sharks pages have the full notes and sources.

Giant oceanic manta (Mobula birostris)
Plate I

Giant oceanic manta

Mobula birostris
Look for
The largest ray, with a wingspan up to about 7 m. Visits cleaning stations.
At Socorro
All season. The Boiler, El Cañón, Cabo Pearce and Punta Tosca, often close to divers.
Scalloped hammerhead (Sphyrna lewini)
Plate II

Scalloped hammerhead

Sphyrna lewini
Look for
A hammer-shaped head with a scalloped front edge and a notch in the middle.
At Socorro
Schools at the Canyon, Cabo Pearce, Roca O’Neal and Roca Partida; deeper when the water is warm.
Whitetip reef shark (Triaenodon obesus)
Plate III

Whitetip reef shark

Triaenodon obesus
Look for
Small and slim, with white tips on the first dorsal and the upper tail lobe.
At Socorro
Piled into the ledges on the east side of Roca Partida by day.
Silky shark (Carcharhinus falciformis)
Plate IV

Silky shark

Carcharhinus falciformis
Look for
A tiny second dorsal fin with a long, thin trailing tip, and long sickle-shaped pectorals.
At Socorro
A resident group circles the boats at San Benedicto; dozens at Roca Partida.
Silvertip shark (Carcharhinus albimarginatus)
Plate V

Silvertip shark

Carcharhinus albimarginatus
Look for
White edges on the tips of nearly every fin.
At Socorro
Resident at the Canyon and Roca Partida, circling the cleaning stations.
Galápagos shark (Carcharhinus galapagensis)
Plate VI

Galápagos shark

Carcharhinus galapagensis
Look for
Stocky and plain grey-bronze, with a broad rounded snout and a tall, upright first dorsal.
At Socorro
Resident at the Canyon, Roca Partida and Cabo Pearce.

Open the Mantas page →

What divers report, site by site

From DAN, Divernet, Scuba Diving and Bluewater Dive Travel. Individual dives vary.

The Boiler (El Boiler), San Benedicto

A pinnacle rising to within about 4 m of the surface: the best site in the islands for giant mantas, cleaned by Clarion angelfish. Dolphins and whitetips too.

Source: Divernet; Divernet; DAN
The Canyon (El Cañón), San Benedicto

Mostly sharks: hammerheads, sometimes in schools of hundreds, silkies, Galápagos and silvertips, at a cleaning station at about 26 m. Mantas visit too.

Source: Divernet; Bluewater 2024
Roca Partida

A bare rock in open ocean that divers circle on each dive: whitetips stacked in ledges, silkies, Galápagos, hammerheads, schools of jacks, tuna and wahoo; humpbacks in season.

Source: Divernet; DAN
Cabo Pearce, Socorro

A finger of rock in the current, with a manta cleaning station at about 21 m, schooling hammerheads and resident bottlenose dolphins that approach divers.

Source: Divernet; Scuba Diving; Divernet
Roca O’Neal, Socorro

Known as “Hammerhead Central”: hammerheads, Galápagos and silkies; lobsters on a plateau at 10–12 m.

Source: Divernet
Punta Tosca, Socorro

Lava formations where dolphins play and mantas circle divers; a tiger shark over 3 m was reported here.

Source: Scuba Diving

Photos

Photos marked “Megan Applegate” were taken at Socorro in December 2023, except a few species she photographed at Cocos Island or Malpelo, which are labelled. The rest come from the sources credited on each page.

Photo Megan Applegate (Socorro)

More information

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