Global environmental change is a defining issue of our time. The ocean is a key component of the Earth system, and yet, in-depth understanding of its roles in sustaining life has not received the attention which it deserves. Humanity must develop a new relationship with the ocean characterized by protection, sustainable production, and prosperity. Society has too much to gain by implementing sustainability solutions and too much to lose by ignoring them. Our actions or inaction now will have far-reaching implications for future of all life on Earth. Ocean blueprint that calls for enforcing 30% Marine Protected Areas by 2030 requires real transformative action. This paper contains new ideas for combining the efforts of natural and social scientists, and traditional users of sea, and explores the potential of modern technologies to assist in this campaign. ‘Smart Sea’ concept introduced in this paper envisages synergies among the problem-solving approaches including digital tools, and eco-engineering and eco-mimicry solution options. Knowledge gaps have been highlighted and relevance of new knowledge systems emphasized together with enabling conditions to address the uncertainties associated with the ocean ecosystem. The ocean has a central position in actions towards preventing global warming of 1.5oC but measures to achieve it should consider that the ocean carbon sink is dynamic and is adversely affected when excessive carbon dioxide produces acidification. The selected measures are likely to have trade-offs, requiring analysis of multiple dimensions, for ensuring sustainable outcomes. The prevailing ocean health and urgency to mitigate it calls for combining global and local solutions, technologies and actions driven by safe and innovative solutions, and wherever possible, based on proof-of-concept. Deviating from the on-going incremental data collection systems to new forms of data-sharing using modern technological tools will contribute to addressing the glaring vacuum in knowledge of the ocean and facilitating a concerted global action for maintaining its ecosystem services. An attempt has been made in this paper to consolidate different opinions and experiences in moving from generalities to specifics for sustainable solutions that support economies, food security and the society.