Close Encounters
Photograph by Brian Skerry

Aquarius has gone native since its installation on Conch Reef in the Florida Keys in 1993. Coral and sponges cover much of its legs and hull, and schools of fish treat it like a section of the reef itself. Seeing the daily parade of neighborhood residents—like this column of schoolmaster snappers—gives the aquanauts a constant education in what creatures live here and how each plays a part in the ecosystem.