Darwin & Wolf

Darwin (formerly Culpepper) and Wolf (formerly Wenman) are the two northernmost Galápagos islands and the only ones north of the equator, lying roughly 160–190 km northwest of the central archipelago — an overnight 14–18-hour sail that puts them beyond day-boat range and makes them a liveaboard-only destination divers plan as a trip of its own. The islands sit where the cool, nutrient-rich Cromwell (Equatorial Undercurrent) and Humboldt currents meet the warm Panama Current, fuelling an extraordinary concentration of large pelagics: a 2016 PeerJ study measured an average shark biomass of 17.5 tonnes per hectare here — the largest reef fish biomass reported anywhere in the world at the time — dominated by scalloped hammerheads (48% of shark biomass) and Galápagos sharks (19%). Darwin's signature site was the iconic Darwin's Arch until its top span collapsed through natural erosion on 17 May 2021; the two remaining stone columns are now generally called The Pillars (the locals' 'Pillars of Evolution'), and diving there continues unchanged. From roughly June to November the same waters host large, mostly >10 m, apparently pregnant female whale sharks — Darwin is the only place in the world where pregnant whale sharks are reliably seen — with August–September the peak. This is unambiguously advanced diving: strong and shifting currents, surge and washing-machine eddies, deep-blue-water entries, and no land visits (the Galápagos National Park permits no landings at either island). Operators typically require an Advanced Open Water certification plus 50+ logged dives and strong-current experience; all diving is strictly within recreational no-decompression limits, and Nitrox is effectively required to keep diving the back end of a week at the islands.

• A 2016 peer-reviewed study (Salinas-de-León et al., PeerJ) recorded an average shark biomass of 17.5 tonnes per hectare at Darwin and Wolf — the largest reef fish biomass reported anywhere in the world to that date — with scalloped hammerheads making up 48% and Galápagos sharks 19% of the shark biomass. Sharks were roughly 73% of total fish biomass.
• Darwin's Arch, long the most famous dive landmark in Galápagos, collapsed through natural wave-and-wind erosion on 17 May 2021, leaving two stone columns now commonly called 'The Pillars' (the 'Pillars of Evolution'). Diving the site is unaffected; only the above-water arch is gone, and landing on the rock was never permitted.
• Darwin Island hosts a seasonal run (roughly June–November, peak August–September) of whale sharks (Rhincodon typus) that are overwhelmingly large, apparently pregnant females — over 700 individuals have been identified, most exceeding 10 m. Researchers believe they use Darwin as a rest stop before giving birth offshore; the Galapagos Whale Shark Project has run the first wild whale-shark ultrasound and blood-sampling work here.