Up close and exotic in the waters of Indonesia's North Sulawesi

On the surface, there is nothing to suggest that the Lembeh Strait would be a better spot for a dive than any other in the area. In fact, with an industrial seaport just down the coast, fishing villages crowding the shoreline and a ceaseless parade of boat traffic plying the channel, it seems an unlikely choice. At first glance, conditions below the surface appear no better: The topography consists of a monochrome black-sand bottom pitted with sickly coral heads and littered with bottles, cans, logs, shoes and other debris. The visibility is, at best, 30 feet, the water a broth of jellies and goop. And yet this muck dive in the company of the North Sulawesi Aggressor's experienced guides quickly reveals just what all the hype is about. In this seemingly barren and lackluster landscape, every solitary sponge or castoff Coke bottle is a potential oasis of life, and the life to be found here is, in its own way, every bit as rewarding as humpbacks or hammerheads.