Although dealing with strictly international maritime areas, the future implementing agreement (ILBI) under UNCLOS currently negotiated raises important challenges as regards the combination and reconciliation of States' individual and collective interests at sea. There is, indeed, a common interest for biodiversity in international maritime areas (biodiversity conservation being a 'common concern of humankind'), which appears not entirely compatible with the individual interest of States at sea, as it focuses mainly on conservation of marine biodiversity, sharing of resources and benefits, access and global integrity of common spaces, rather than on exploitation and geostrategic or individual economical interests. How to concretely reconcile, then, in the international spaces, the individual interests of coastal and non-coastal States and the common interest of the international community? How could the future agreement take those interests into account? The purpose of this article is to suggest a different prism for analysing the gaps and challenges regarding the current law of the sea regime in the field of marine biodiversity and the adoption and content of a new UNCLOS implementing agreement. Among all the available options under scrutiny in the context of the discussions related to the adoption of a new implementing agreement under UNCLOS, some are more likely to reconcile individual and common interests at sea than others. It appears necessary to place the cursor where the equilibrium between those interests is best preserved in order to ensure simultaneously a sufficiently voluntary conclusion and implementation of the future agreement and the effective and sufficient achievement of the treaty objectives.