how much of the ocean is explored

As of 2025, about 27.3% of the global seafloor has been mapped with modern high-resolution technology, but actual exploration of the ocean seafloor by humans and submersibles has been extremely limited, with less than 0.001% of the deep ocean floor directly seen or explored. Generally, it is estimated that only around 5% of the entire ocean has been explored in terms of detailed biological, chemical, and geological study, leaving over 80% of the ocean largely unexplored or unknown. The vast majority of the ocean, especially the deep ocean regions, remain a mystery with ongoing exploration efforts continuing to uncover new species, features, and insights.