Scalloped Hammerhead Shark

Photo: Nicholas Hess · CC BY-NC

Schools of scalloped hammerheads aggregate in the cold nutrient-rich upwellings off Cape Marshall, particularly during the garúa season from June to November when Cromwell Current influence is strongest. These sharks use the site as a cleaning station and aggregation point, often appearing in groups of dozens or hundreds along the deeper wall. Their preference for cooler thermocline waters means encounters are more likely at depth, where divers may find themselves surrounded on all sides.