San Pedro Nolasco Island – San Carlos & Guaymas

Site Overview

San Pedro Nolasco Island is the signature dive site of the San Carlos and Guaymas region, featuring a thriving California sea lion colony, dramatic rocky walls covered in gorgonian sea fans, and abundant reef fish populations that make it the most visited offshore diving destination in the upper Sea of Cortez. The island's volcanic origins created varied underwater topography with rocky slopes descending from the surface to 25 metres, interspersed with vertical walls, ledges, and boulder fields that provide diverse habitats for an impressive range of marine species. The resident sea lion colony numbers over 200 individuals with juveniles regularly approaching divers for curious interactions including fin-tugging, bubble-blowing, and acrobatic barrel rolls that create extraordinary photographic opportunities. Schools of jacks, yellow snapper, and creole fish patrol the reef slopes in large numbers while moray eels occupy every suitable crevice in the rocky substrate. Green sea turtles visit during the warmer months, gliding gracefully along the walls while feeding on algae and invertebrates. The gorgonian sea fans are among the largest and most colourful in the Sea of Cortez, extending their polyps into the nutrient-rich current and providing excellent macro photography subjects alongside the wide-angle opportunities. The island's moderate distance from San Carlos harbor makes it accessible for day trips while its protected status ensures healthy marine ecosystems with abundant, unafraid marine life throughout the diving season.