The first hour was wonder. Light bent in green shafts through columns of kelp taller than houses. I floated between hydrothermal vents that puffed mineral smoke and neon anemones that opened like curious eyes. A reefback cruised by, eyelashes of barnacles sparkling—its belly a field of coral gardens and tiny fish that sought shelter in its slow orbit. For each marvel there was an undercurrent of something else: the faint, metallic echo of machinery; a language of groans from metal ribcages half-buried in silt. The ocean told me it held both cathedral and cemetery.