For this photograph, I dove down and settled on the bottom of the Rio Negro, where the normally exposed riverbank lay submerged under nearly five feet of high-water flood. As I sat quietly on the silty floor, a curious Amazon river dolphin drifted toward me, seemingly just as interested in me as I was in it. We hovered there together in the tannin-dark water, studying one another in a rare moment of shared curiosity. Capturing this interaction in a place that is usually dry land—and with such a naturally inquisitive animal—made the encounter unforgettable.