Diving Malpelo: Hammerhead Schools on a Rock in the Open Pacific

Malpelo is a single volcanic island roughly 3 km long and 700 m wide, plus a scatter of offshore rocks, rising from deep water about 500 km west of Buenaventura on Colombia\'s Pacific coast. Nothing grows on it beyond lichen and algae, and the only human presence is a small Colombian Navy detachment. The surrounding waters were declared the Santuario de Fauna y Flora Malpelo, one of the largest no-fishing zones in the eastern tropical Pacific, and the sanctuary was inscribed as a UNESCO World Heritage Site in 2006.

It sits inside the Eastern Tropical Pacific Marine Corridor along with Cocos, Coiba, Galapagos and Gorgona, and shares their character: cold upwelling, nutrient-rich water, low coral cover and enormous aggregations of large animals. The diving is on submerged pinnacles, walls and boulder fields around the island, at 15 to 40 m, almost always in current, always in blue water with a very deep bottom under you. This is not a reef destination and photographers who come for macro will be disappointed.

Permit, quota and access

Entry to the sanctuary is controlled. Parques Nacionales Naturales de Colombia issues a limited number of diving permits each year, caps the number of vessels present and limits how many divers may be in the water at once, and the boat must carry authorisation before it sails. In practice this is arranged entirely by the liveaboard operator months in advance; there is no way to turn up and dive. A sanctuary entrance fee for foreign visitors applies on top of the trip and is normally billed by the boat.

There is no land-based option and no day trip. Every visit is a liveaboard, typically eight to eleven nights, sailing from Panama City in Panama or from Buenaventura in Colombia, with a crossing of roughly 30 to 40 hours each way in open Pacific swell. Divers spend four or five days on the rock itself. Nobody may land on the island without a separate scientific permit.

Malpelo is one of a very small number of places on earth where large sharks still aggregate in numbers that predate industrial fishing, and its remoteness and quota system are the reason.

• Scalloped hammerhead schools: the reason the sanctuary exists. Schools of dozens to several hundred animals move along the pinnacles and cleaning stations, most consistently in the cool, thermocline-rich months from January to May.
• Walls of silky sharks: hundreds of silkies gather in the shallows and around the boat, often on the safety stop, which is an experience unlike anything on a reef.
• Galapagos sharks in numbers: large, curious and resident, patrolling the deeper rock faces alongside whitetip reef sharks.
• The smalltooth sand tiger: Malpelo is one of the very few places in the world where Odontaspis ferox is seen with any regularity, though it lives below recreational depth and sightings are rare and mostly limited to deep or technical divers.
• A genuine no-take sanctuary: a permit quota, capped vessel numbers, a permanent navy presence and one of the largest no-fishing zones in the region, which is visible in the biomass.
• Endemic species on a bare rock: the Malpelo barnacle blenny and several other fish and land species occur nowhere else, and the island holds a huge colony of Nazca boobies.

All sites are within a short tender ride of the island, on the main rock or on the satellite pinnacles around it. The dive plan is set by swell and current on the day, and negative entries from a moving tender are routine.

La Nevera

The Fridge, named for the cold upwelling that pushes through it, and the most reliably productive site on the island. A rock face and boulder slope where hammerheads come in to cleaning stations, with divers holding position out of the current behind rocks and watching the schools pass. Thermoclines here can drop the temperature several degrees in a single dive, which is precisely why the sharks come.

El Arrecife

The Reef, a boulder and rock slope on the eastern side with more structure than most Malpelo sites. Whitetip reef sharks stack up in the crevices, moray eels are everywhere, and the site holds the largest concentration of fish life on the island. A good first dive of a trip for reorienting to the conditions.

Los Tres Mosqueteros

The Three Musketeers, a set of three rock pinnacles off the southern end of the island rising from deep water. Exposed, current-swept and open on all sides, which is why they draw hammerheads, Galapagos sharks, big jack schools and, in season, whale sharks. One of the more demanding sites when the current runs.

El Bajo del Monstruo

Monster Rock, a submerged pinnacle whose top sits around 25 m, dived by descending fast into open water and finding the structure. It has the strongest reputation for large hammerhead schools and for the deep encounters that Malpelo is known for. Blue water, no reference and real current: an experienced-diver site.

La Gringa

A wall and boulder site on the western side, generally more sheltered than the southern pinnacles and often used when swell rules out the exposed sites. Galapagos sharks patrol here, moray eels fill the cracks, and schools of creolefish and bigeye jacks move over the rock.

El Altar de la Virgen

A rock face on the northeastern side, named for a small shrine on the island above it. A steep drop with cleaning stations that hammerheads and Galapagos sharks use, plus dense schools of barberfish doing the cleaning work. Silky sharks are frequently overhead in the shallows here at the end of the dive.

El Acuario

The Aquarium, a shallower and more sheltered site among the rocks close to the main island, used as an easier dive, a checkout dive or an afternoon site when conditions are difficult. Whitetip reef sharks, moray eels, hogfish, king angelfish and the endemic barnacle blennies in the rock.

Sahara

A sand and rubble slope, unusual at Malpelo where almost everything is rock, running down from the boulder line. Rays and bottom-dwelling species here, plus the chance of hammerheads coming in over the sand, and it is one of the sites where deep-dwelling species have been recorded at the limits of visibility.

Surveys of the sanctuary record around 400 fish species, 17 shark species and a number of endemics. Coral cover is minimal and the rock is dominated by algae, barnacles and encrusting life; the biomass is in the water column.

Sharks

• Scalloped hammerheads in schools, from dozens to several hundred animals, most consistent from January to May.
• Silky sharks in large numbers in the shallows and around the boat, frequently on the safety stop.
• Galapagos sharks, resident, large and often inquisitive, along the deeper rock faces.
• Whitetip reef sharks stacked in the crevices at El Arrecife and El Acuario.
• Whale sharks, seasonal and unpredictable, most often reported in the warmer, wetter months.
• Smalltooth sand tiger sharks, a rare deep-water species for which Malpelo is one of the few known sighting locations; they sit below recreational depth and are not a realistic target for a normal dive.

Other pelagics

• Large schools of bigeye and black jacks, and clouds of creolefish over the pinnacles.
• Yellowfin tuna, wahoo, rainbow runners and bonito in the current.
• Pacific manta and mobula rays, and marbled rays over the sand at Sahara.
• Bottlenose dolphins and, occasionally, humpback whales on the surface from July to October.

Rock and endemic life

• Moray eels in extraordinary density, filling every crack on several sites.
• The Malpelo barnacle blenny, endemic to the island, living in vacated barnacle shells on the rock.
• King angelfish, Mexican hogfish, panamic soldierfish and barberfish working the cleaning stations.
• Nazca boobies breeding on the island in large numbers, along with endemic land crabs and a lizard found nowhere else, all seen from the boat.

Surface water is typically 24 to 28C, but Malpelo is defined by its thermoclines: cold upwelling can drop the temperature to 16 to 20C within a single dive, sometimes abruptly at 20 or 25 m. That cold water is what brings the hammerheads in, so the best diving and the coldest diving are the same diving. A 5 mm full suit with a hood is the working minimum and many divers use 7 mm or a semi-dry, particularly from January to May.

Visibility runs 15 to 40 m, generally clearest from January to April and reduced in the rainy months when plankton and runoff-free but nutrient-heavy water move through. Current is constant and can be strong, changing direction and strength with depth, with downcurrents on the exposed pinnacles. Entries are usually negative from a moving tender and dives end in blue water with a surface marker buoy and a tender pickup in open swell.

Operators require Advanced Open Water at minimum, commonly around 50 logged dives and often 100, with recent experience of current and blue-water diving. Nitrox is standard on the boats and strongly recommended for four dives a day at 25 to 35 m. A surface marker buoy, a signalling device such as a whistle and a mirror, and ideally a personal locator beacon are expected kit. There is no shelter, no shore facility and no recompression chamber within a day and a half; dive insurance with evacuation cover is mandatory in practice.

Malpelo is dived for most of the year, but boats concentrate on two windows and the diving changes noticeably between them. The trade-off is between cold, clear water with the biggest hammerhead schools and warmer, wetter conditions with a better chance of whale sharks.

• January to May: the peak. Cool upwelling, pronounced thermoclines, the best visibility of the year and the largest and most consistent hammerhead schools. Also the coldest water, with thermoclines into the high teens, so bring more neoprene than the latitude suggests.
• June to August: the transition, with warming water, rising rainfall and a mix of conditions. Hammerhead numbers drop but silky sharks remain abundant and humpback whales pass through the region from July.
• September to November: the warmest and wettest period, with 27 to 29C water, lower visibility and less current. Whale shark sightings are most often reported in this window, and boats are less full.
• December: the turn back towards the cool season, with thermoclines returning and hammerhead numbers building. Seas can be lively as the crossing conditions change.
• Crossing weather matters as much as the diving: the run from Panama or Buenaventura is 30 to 40 hours of open Pacific in both directions, and swell is generally lower from February to April.

Malpelo is reachable only by liveaboard, and there are two departure points. Most trips sail from Panama City in Panama, arriving via Tocumen International Airport (PTY), which has the widest international connectivity in the region with direct flights from North America, Europe and across Latin America. The crossing from Panama takes roughly 35 to 40 hours each way.

The Colombian option is Buenaventura, the nearest port to the island at about 500 km, with a crossing of roughly 30 to 36 hours. Buenaventura has a small airport (BUN), but in practice travelers fly into Alfonso Bonilla Aragon International Airport (CLO) at Cali and continue by road, about three hours, usually on an operator-arranged transfer. Trips from Buenaventura often combine Malpelo with Gorgona Island.

Itineraries are typically eight to eleven nights, with four or five diving days at the rock and the remainder spent crossing. Some operators run longer combined itineraries linking Malpelo with Coiba in Panama. Because the permit is tied to the vessel and issued in advance, dates are fixed and there is no flexibility to extend on arrival.

Most Western nationalities enter Colombia visa-free for up to 90 days, and Panama visa-free for 90 to 180 days depending on nationality. Yellow fever vaccination is recommended for parts of Colombia and may be requested; check current requirements and give your operator passport details well in advance, since the sanctuary requires a manifest for every vessel.

Permit and fee: entry to the Malpelo Fauna and Flora Sanctuary is capped by an annual diving quota administered by Parques Nacionales Naturales de Colombia, which also limits the number of vessels present and the number of divers in the water at one time. The permit is obtained by the liveaboard months in advance. A sanctuary entrance fee for foreign visitors, on the order of USD 40 to 60 per person, is normally billed by the boat on top of the trip price; confirm the current amount at booking.

Rules: the sanctuary is entirely no-take, with no fishing of any kind. Landing on the island is prohibited without a scientific permit. No touching, no gloves for holding onto animals, no anchoring, and a surface marker buoy on every dive. The Colombian Navy detachment on the island monitors the sanctuary and boats are checked.

Money: the Colombian peso is the national currency, but liveaboards operating out of Panama and Buenaventura generally bill in United States dollars. Carry cash for park fees, crew tips and anything not settled by card, since there is nothing at sea.

Diving: nitrox is standard on Malpelo boats and effectively required for the profiles. There is no recompression chamber anywhere near the island; the nearest facilities are on the mainland, more than a day away by sea, so dive insurance with evacuation cover and conservative profiles are not optional.

Practicalities: Colombia runs 110 V with type A and B sockets and sits on UTC-5 year-round; Spanish is the language, and boat crews working the international market speak English.

• Book a year ahead: the permit quota and the small number of vessels mean the good dates in the January to May window sell out well in advance.
• Bring more exposure protection than you think: thermoclines drop into the high teens on the best hammerhead dives. A 7 mm or semi-dry with a hood, and gloves, are normal here.
• Take a reef hook and know how to use it: hammerhead watching at La Nevera means holding position out of the current without touching living rock.
• Carry redundant signalling: DSMB, whistle, mirror and ideally a personal locator beacon. Pickups are in open swell far from anywhere.
• Prepare for the crossing: 30 to 40 hours of open Pacific in each direction. Take seasickness medication before you sail rather than after it starts.
• Dive nitrox and plan conservatively: four dives a day at 25 to 35 m with no chamber within a day and a half of the island leaves no margin for a bent diver.
• Set expectations on the sand tiger: the smalltooth sand tiger lives well below recreational depth. It is a famous Malpelo animal and it is not something a recreational diver should plan to see.