Our experience of the blue-water marine environment has been largely superficial, risky, and in every case mediated by technology: ships and boats, nets, depth lines, and so on. Therefore it is not surprising that a new understanding of marine spaces was begun by fisheries science. Around 1900, early fisheries biologists approached the marine environment as natural historians approached terrestrial wildernesses—spaces needing inventorying and cataloging. Marine ecologists, “working entirely in the dark” until the 1950s, tried to measure and understand the remote and invisible marine environment. Even while new technologies revealed the ever-changing, yet largely featureless ocean expanses, most environmental changes remained invisible without instruments to monitor thermoclines, salinities, plankton productivity, and other features. Scientists tended, therefore, to view the ocean environment as cyclical and perhaps predictable. Moreover, fisheries biologists' approaches were informed by terrestrial analogies as they employed reductive strategies to coax efficiencies of production from the ocean environment. This essay explores analogies from agricultural production, forestry management, and Gospel of Efficiency conservation in the early twentieth century that led scientists to see marine spaces as robust and resilient, and informed efforts to transform ocean spaces into static management areas with artificial borders. Only after scuba gear and undersea cameras were introduced in the 1950s did scientists begin to engage with the dynamic nature of the biological marine environment.