Where to see Scalloped Hammerhead Schools in 2026

Best months

Difficulty & experience

Best locations

• Cocos Island

  Costa Rica

  primary

  Liveaboard-only seamount with reliable hammerhead aggregations at cleaning stations.

• Wolf Island

  Ecuador

  primary

  Northern Galápagos current convergence; one of the densest schooling sites in the world.

• Darwin Island

  Ecuador

  primary

  Sister site to Wolf with comparable aggregation density.

• Malpelo Island

  Colombia

  primary

  UNESCO-protected seamount with hammerhead and silky shark aggregations.

• Socorro Islands

  Mexico

  secondary

  Hammerheads appear seasonally alongside the more famous giant manta encounters.

Sites at these locations

• Bajo Alcyone

  Cocos Island, Costa Rica

  Submerged seamount 25 m below the surface, rising from the deep. Hammerhead schools in the hundreds patrol the up-current edge. Cold thermocline, surge, and current — the most famous dive in the Eastern Pacific.

• Darwin's Arch (The Pillars)

  Darwin Island, Ecuador

  Liveaboard-only seamount off the remote Darwin Island. Schooling scalloped hammerheads in the hundreds, whale sharks in season, silky sharks circling the surface. Strong current, surge, cold thermoclines, and the second-best shark-density site on the planet. The arch itself collapsed in 2021; the pillars remain.

• Shark Bay (Wolf Island)

  Wolf Island, Ecuador

  Northern point of Wolf Island where hammerhead schools sweep through in the hundreds. Hook into the rocks at 18 m, watch the sharks pass at arm's length. Whale sharks in season; dolphin pods occasionally crash the dive.

• The Landslide (El Derrumbe)

  Wolf Island, Ecuador

  A boulder slope on Wolf Island's southeast corner that looks like the cliff let go yesterday — broken rock and rubble spilling into the blue. Drop to 10 m and work down to a cleaning station where scalloped hammerheads stack up by the dozen while barberfish pick them clean. Galápagos sharks patrol the edge; from June to November whale sharks, many of them pregnant females, cruise the deep water beyond. Moray eels jam the cracks, and eagle rays and yellowfin tuna ride past in the current.

• Dirty Rock (Roca Sucia)

  Cocos Island, Costa Rica

  Cluster of jagged pinnacles off Cocos's northwest corner, streaked with guano that gives the rock its name. Drop down a wall to 20–25 m and hold position at the barberfish cleaning station — scalloped hammerheads queue overhead in schools that can number in the hundreds, sliding in one at a time to be cleaned. Galapagos sharks, marbled rays, and bigeye trevally fill the blue between passes. Strong current and surge are the price of admission.

• The Boiler

  Socorro Islands, Mexico

  A submerged volcanic pinnacle off the northwest side of San Benedicto Island, rising from roughly 40m to within about 6m of the surface. Named for the way swell breaks over its two 'horns' and makes the water appear to boil, the site functions as a giant manta cleaning station where Mobula birostris are tended by clarion angelfish and routinely engage divers at close range. Bottlenose dolphins, multiple shark species and the occasional humpback whale song round out a small, circumnavigable seamount that can be looped twice in a single dive.

Plan a trip

Methodology