Which crewed submersible made record dives to the deepest points of all five oceans?

The crewed submersible that made record dives to the deepest points of all five oceans was DSV Limiting Factor.

The two-person vehicle was designed for full-ocean-depth operations and piloted during the Five Deeps Expedition by explorer Victor Vescovo. It became the first crewed submersible to reach the deepest point in each of the Atlantic, Southern, Indian, Pacific, and Arctic oceans.

Its dives included the Puerto Rico Trench, South Sandwich Trench, Sunda or Java Trench, Challenger Deep in the Mariana Trench, and Molloy Deep. In the Pacific, Limiting Factor also completed repeated descents to Challenger Deep, the deepest known point on Earth. The vehicle was supported by the research ship DSSV Pressure Drop and deep-sea landers.

The name can cause confusion because Limiting Factor is a submersible, not the expedition itself. It was later renamed Bakunawa after being sold in 2022, but its record-setting dives were made under the original name. Shinkai 6500 and DSV Alvin are important research submersibles, but neither completed this five-ocean feat.