What about managing a planet, when almost all the largest habitat is visually unexplored? The oceans of the earth occupy nearly 70 per cent. of the earth, but direct, close inspection of the deep bottom is becoming more and more a rarity. A summary of submersible diver logs underlines the fact that human eyes, be it behind a viewport or viewing a live camera image, have not been at all gazing on an underlying state more than 200 meters (656 feet), the generally accepted line that delineates the sunlit zone and the deep ocean. Beneath that line, the bottom of the sea is black, and the pressure increases, the temperatures drop and the logistics of any expedition is an engineering project rather than a scientific one.
The scale problem is brutal. The average depth of the ocean is approximately 3,682 meters (12,080 feet) and the deep ocean occupies the majority of the ocean both in terms of volume and area. Even an optimistic thought experiment hundreds or thousands of competent vehicles all surveying consistently, day-after-day-after-day, reaches into geological-sounding timescales before “seeing it all” becomes plausible. Such gap is important as images can do things that maps cannot: they demonstrate communities of organisms in situ and they demonstrate how animals relate to rocks and sediments and record delicate features that might otherwise remain concealed in bathymetric contours.
Maps however are the entry point. By June 2025, 27.3% of the global seafloor had been mapped to modern high-resolution standards, a small but substantial step in mapping future dives and selecting representative study sites. Nonetheless, high-resolution sonar not only fails to tell a species, but it also fails to tell whether a slope is overlaid with living corals or bare basalt. There is no other way that “likely habitat” can become documented ecosystems other than through visual surveys.
Another less noisy problem than depth or cost is sampling bias. The history of deep-diving expeditions compiled demonstrates that the vast majority of visual coverage is concentrated on a limited number of Exclusive Economic Zones, with only a few countries taking up the disproportionate share of all dives. The danger that the researchers summarized in a straightforward way is that this tiny and skewed sample is not representative of trying to characterize, comprehend, and control a global ocean. When a camera gaze turns back to the well-known waters again and again, the conclusions concerned with the whole world are constructed on the basis of the exceptions pertaining to a particular area.
Engineering is starting to make it change on the margins. An autonomous underwater vehicle has been built specifically to operate in extreme depths and it has gone under 5,600 meters and captured images of regions of the seabed previously not seen directly. During that mission, polymetallic nodules were spotted at 5,645 meters, which demonstrates the ability of robotics to increase access and acquire uniform baseline imagery. According to Adam Soule, “The greatest need right now is baseline data, which requires very specialized tools.”
Baseline data is not an abstract scientific whim; it is the point against which all that comes afterwards can be gauged; biodiversity inventories, habitat comparisons, and any other legitimate effort to determine change with time. It is also tangent to an ancient enigma: how numerous species there are that reside in the sea. It is estimated by researchers that there are 700,000 to 1 million marine species (not including the majority of microorganisms), and nearly 2,000 new species per annum are accepted in the scientific community. Remote, dark and difficult to sample, the deep sea is one of the probable reservoirs of much of that which has not yet been described.
The headline figure concerning the visual coverage of the deep seafloor is, thus perceived, not a fact of trivia but rather an acknowledgement of design. The future of ocean wisdom lies in the development of devices that can operate longer, go deeper, and travel longer distances while also expanding the geographic location of exploration, thus the largest environment of the planet is not reflected by a small piece of it.
