The chapter analyzes the conflict between nascent bright green environmentalism and well-established fossil fuel-based developmentalisms, set against a backdrop of global population growth and resource concerns in the 1970s. It addresses the questions of how and why fossil fuel-based developmentalism contributed to the prolonged marginalization of bright green environmentalist ideas about zero-carbon offshore energy generation. Intellectually, architect Kikutake Kiyonori and engineer John P. Craven faced the spatial constraints inherent in island contexts, in this case Hawai’i and Japan. They focused on employing technology to decouple socio-economic development from ecosystem service and resource overexploitation to enable continuous industrial growth. Applying an oceanic-vertical perspective to island ecosystems and their littoral marine regions gives insights in some of the origins of zero-carbon energy technologies like offshore wind, floating solar photovoltaics, and floating nuclear plants. US and Japanese governmental support for already feasible offshore oil and gas exploitation and terrestrial energy generation nevertheless marginalized these ideas for decades.