Cabo Marshall

Cabo Marshall sits on Isabela's northeastern coast, in the shadow of the still-active Wolf Volcano, and the dive follows the shoreline rather than circling a fixed mooring. Pangas drop divers close to a rocky plateau at around 10 to 12 metres, and the recommended entry is a negative descent straight onto it — swell at the surface here can be heavy enough to make anything slower uncomfortable. From the plateau the wall continues down past 30 metres for those who follow it, though most of a dive is spent holding shallow and watching the blue.

The plateau functions as a cleaning station and is the best-documented manta site on the western circuit: oceanic manta rays, the largest ray species alive, circle it on their own schedule rather than a predictable timetable, sometimes passing within a few feet of a diver holding still. Scalloped hammerheads, spotted eagle rays, yellowfin tuna and schools of Pacific creolefish work the same stretch of wall and open water, and liveaboards often schedule two dives here across a day to improve the odds of a manta pass.

Visibility can shift within a single dive as the tide turns — divers report everything from a few murky metres to open water later in the same session — and the current, while genuinely present, runs noticeably gentler than the surge at Darwin or Wolf. Guides brief on current direction before each entry and adjust the route along the shoreline accordingly.