E/V Nautilus Begins 20-Day Expedition into Unsurveyed Hawaiian Waters and Papahānaumokuākea
Ocean Exploration Trust and partners have launched the final 2026 voyage of E/V Nautilus, mapping and diving on unmapped seamounts at the eastern edge of Papahānaumokuākea Marine National Monument with a ten-person Hawaiian science team aboard.
On October 4, 2026, Ocean Exploration Trust and partners launched their final 2026 deep-sea expedition aboard E/V Nautilus, a 20-day voyage into some of the least-surveyed water in the Hawaiian archipelago. The ship set out to deploy remotely operated vehicles to depths of up to 6,000 meters and run multibeam acoustic mapping across unmapped seamounts, bathymetric ridges, and abyssal plains along the eastern fringes of Papahānaumokuākea Marine National Monument and in the waters southwest of the Main Hawaiian Islands.
The expedition is the sixth OET has run in 2026 and the 19th in Hawaiian waters since 2018, and it carries a notably local crew. Ten Hawaiian scientists, students, and educators are sailing aboard Nautilus for the full 20 days, and the work itself — ROV dives and seafloor mapping designed to characterize deep-ocean habitats, biodiversity, and geological formations in Papahānaumokuākea — is being live-streamed via telepresence to NautilusLive.org. Every dive and every kilometer of mapping data goes into a publicly archived record afterward, which means the public-facing stream and the long-term archive are both part of the deliverable, not just the live show.
That distinction matters because the destination, by design, is a place where almost no one has been. The eastern edge of Papahānaumokuākea and the abyssal plain southwest of the Main Hawaiian Islands are exactly the kind of terrain that multibeam sonar routinely reveals to be more complicated than the low-resolution charts it replaces — isolated seamounts, ridge spurs, and volcanic edifices that have never been imaged at high resolution, let alone visited by a vehicle with lights. A 6,000-meter-rated ROV paired with a hull-mounted multibeam is the standard toolchain for that work, and OET has now run more than 180 such expeditions since 2009, with Hawaii as the single most-visited region in the program.
The honest framing for a story like this is also worth being explicit about. No one is going to come back from a 20-day expedition having “discovered” a habitable world, and the more interesting frame is the duller one: that the deep Pacific is still, in 2026, mostly a low-resolution surface. A few hundred thousand square kilometers of seabed going from a fuzzy coarse grid to a precise multibeam map, plus a couple of dozen ROV dives sampling whatever is actually down there, is the actual product. For Papahānaumokuākea specifically — a monument whose management depends on knowing what is and isn’t in the water column and on the seafloor — that baseline mapping is the kind of work that quietly determines whether future protections are well-targeted or not.
The expedition also makes the data path unusually legible. Because every dive is streamed live and every dataset ends up in a public archive, a marine biologist in Hilo, a graduate student on the continent, or a curious member of the public can follow a dive in real time and then download the resulting bathymetry or biological observations afterward. That is a real shift from the era when deep-sea expeditions left behind only the published papers, and it is one of the more practical reasons programs like this keep returning to the same region year after year — the cumulative archive of a 19-expedition Hawaiian series is itself a scientific resource, not just a sequence of individual trips.