how much of the ocean have we explored

As of 2025, humans have mapped about 27.3% of the global seafloor with modern high-resolution technology, but this is primarily mapping, not direct exploration. In terms of actual direct exploration, humans have visually observed less than 0.001% of the deep ocean seafloor, which is roughly an area the size of Rhode Island. Over 90% of the ocean is deep ocean (deeper than 200 meters), and the vast majority of this remains unexplored. Therefore, while we have some knowledge from mapping and indirect methods, direct exploration and observation of the ocean remain extremely limited. Overall, more than 80% of the ocean remains unexplored.