The ocean is a fundamental economic and environmental engine providing the services that are critical for the success of every economy and the very survival of life on our planet. And yet, it is seriously neglected with little formal value placed on the complex web of those life-giving ecosystem services. Should we choose to credit these services with their true value, we would find that the ocean is worth orders of magnitude more than the amount we are currently investing in it. Today, the majority of marine investments fail to effectively target a transition to a sustainable ocean economy, focusing instead on a predominantly extractive model which includes infrastructure projects, energy provision, commercial fishing and tourism. Despite the ocean’s scale and importance, climate finance is unfairly skewed away from nature-based solutions – and the little investment in nature that occurs is generally directed towards better understood or more visible terrestrial ecosystems. Of the very limited capital that is mobilised for sustainable ‘Blue Carbon’ projects, the evidence suggests that it is exclusively spent on protecting and restoring coastal saltmarshes, seagrasses and mangroves, with deep and open ocean ecosystems entirely overlooked.