What percentage of Earth's oceans have been explored?

~29% mapped

Planet

As of April 2026, 28.7% of the sea floor has been mapped at modern resolution, according to the Seabed 2030 project, up from about 6% in 2017. Only a small fraction of that has been seen directly by cameras or submersibles. The ocean covers 71% of the planet and averages about 3.7 km deep.