Innovation of the Deep (no audio version)
Learn about the cutting-edge technologies used for unprecedented deep-sea exploration.
Learn about the cutting-edge technologies used for unprecedented deep-sea exploration.
This is the third chapter in a four-part series about an endeavor to discover, explore, and map the depths of our planet's oceans in ways that have never been done before. In part one , we were introduced to Caladan Oceanic, what its goals are, and why they matter to humanity. Part two profiled some of the remarkable people who have been integral to the success of Caladan's missions. Now, let's learn about the amazing advances in technology that have made it all possible...
Without trivializing the astounding inventions that have made human spaceflight possible, it is fair to point out that deep-sea exploration comes with its own set of difficulties, and its associated feats of engineering are every bit as much of a marvel.
Vehicles designed for both destinations ultimately need to keep their occupants safe: one from the freezing vacuum of space, the other from the almost unimaginable pressure of the deep. Undersea communication and navigation face unique hurdles, considering the ease with which light and radio waves can pass through the void of space, but not water. And then, of course, there’s that pesky thing called gravity that is constantly a factor here on Earth.
Victor Vescovo started his company, Caladan Oceanic , with an ambition to personally dive to the Five Deeps —the deepest point in each of the world's five oceans. That discrete goal blossomed into a rigorous, wide-ranging scientific expedition spanning two years thus far, with plans to continue into 2021 and beyond. To accomplish all that they have, Victor and his Caladan team had to combine four major technological components in innovative ways:
The four sections below will take a look at each of these components, while painting a picture of how they all complement each other to transform humanity's ability to access some of the most mysterious places on our own planet.
Note: The original version of this story contains audio clips that relate key information and add useful context. To read that version, click here .
We didn't want to build another one-hit wonder that would make a single dive and then end up in a museum somewhere. —Patrick Lahey, Triton Submarines
Human descent to Challenger Deep, the deepest point in Earth’s oceans, was first achieved six decades ago. Until Victor and Caladan came along, though, it had been up against a barrier that it shared in common with space travel: inability to return repeatedly.
To produce a submersible capable of diving to such extreme depths over and over again, Victor turned to industry forerunners Triton Submarines . The Triton team came up with a vehicle that has completely rewritten the book on how we can learn about the once-hidden portions of our oceans. Before we talk about Triton's creation, however, it helps to understand a little bit about how far deep-sea exploration had already come.
It took over a half century for another human to descend to Challenger Deep, when filmmaker James Cameron took the plunge in the Deepsea Challenger in 2012. In that same span, humankind landed on the moon, sent probes beyond the furthest limits of our solar system, and established a permanently habitable station in Earth's orbit. Why was there such a big gap, then, in the progress of deep sea exploration?
One common-sense theory is that the cosmos was prioritized, thanks in large part to Cold War-era nationalistic competition and outer space's allure to the human psyche. Try to read about the Voyager project, for instance, without being gripped by existential awe. In comparison, fairly or not, the ocean was simply less mysterious, exotic, and contested, and thus less captivating.
Victor posits an additional hypothesis: Much of the sea's "eye candy," the visible life that is more likely to capture the imagination of the general public, is contained in its uppermost 2,000 meters. Most oceanographic efforts, private and public alike, have tended to focus their attention in those zones. The deeper reaches, in contrast, are dark, "desert-like," and sparsely populated. Though they may have seemed like an afterthought to most of the world, Victor saw in them a chance to make a difference in expanding critical human knowledge. He just needed the right people and the right tools.
They were all saying what a jump [the Deepsea Challenger] was from the Trieste, but you can argue that the jump from [the Deepsea Challenger] to the Limiting Factor is almost as big. —Master Mariner Stu Buckle, captain of the Pressure Drop
Enter the Limiting Factor
Patrick Lahey, President of Triton Submarines, was presented with an enormous opportunity when Victor arrived at his door, Five Deeps itinerary in hand. It was imperative that the vehicle his team would design to carry out these record-setting dives be more than a flash-in-the-pan gimmick, as Patrick expresses here:
"At the end of the day, I go back to this idea that I’m in this because I love what I’m doing. I genuinely love the ocean, I’m passionately interested in the ocean, and encourage other people to take an interest in the ocean. And so as a manufacturer, it’s not going to advance that agenda to just build something that maybe achieves the goal but doesn’t actually move the ball down the field or accomplish anything more meaningful than that."
To that end, Patrick and his team laid out a number of essential parameters for Victor's machine that would help ensure its place as a groundbreaking vessel.
In the scene below, examine a 3d model of the Limiting Factor and learn about the technological aspects that have made it such a unique vehicle. Click on a feature's label or bubble to learn more about it; orange leader lines represent navigation-related equipment, while purple lines indicate scientific and data-collection accessories.
Finally, the Triton team insisted on one additional aspect that would truly make the Limiting Factor a revolutionary vessel for exploration: accreditation by a respected organization. More than any material advancements—thicker acrylics, new kinds of synthetic foam, etc.—Patrick and John Ramsay, Triton's principal design engineer, give this factor the greatest weight in the leap achieved by their sub.
A document from DNV GL attesting to the Limiting Factor's depth capabilities.
John points out that people don't think twice about flying on airplanes in large part because "the FAA doesn't let companies police their own designs." Just like cars, airplanes, elevators, and most potentially dangerous but widely used technology, there is a process through which a submarine can be inspected on a reoccurring basis by an independent entity and deemed safe for its intended purpose.
Triton called on Norwegian-German classification registrar DNV GL to scrutinize the Limiting Factor's safety and durability. Jonathan Struwe, an inspection engineer with DNV GL, even accompanied Patrick on a Challenger Deep descent during the Five Deeps expedition in 2019.
Designing the submersible to meet accreditation standards made the process more arduous for the Triton team—particularly for John Ramsay—and more expensive for Victor. In the end, though, it gave the Limiting Factor a credibility that no other hadal zone-capable vehicle in the world had. This was an invaluable asset to Victor's ability to freely invite scientists, experts, and even paying customers on dives to the deepest parts of the oceans. It also ensures that Caladan remains a going concern, moving forward in search of new discoveries.
It was designed...to be a sub-hunting vessel —Victor Vescovo
As soon as the ink dried on Caladan's contract with Triton, Victor and his team turned their attention to an equally vital piece of infrastructure: a ship that would be capable of hauling the Limiting Factor from dive spot to dive spot and launching the sub—all while housing expedition participants and crew at sea for weeks at a time.
It was Triton that identified a ship that had been sitting practically derelict in a Seattle waterway. A relic of the late Cold War, the "T-AGOS"-class vessel was one of fewer than twenty of its kind ever built. These ships hit the seas during the mid-1980s as part of an underwater sub-surveilling system using an array of sensors towed on a cable. In other words, Victor points out, "This was a sub-hunting ship."
The Pressure Drop on the open water.
This particular specimen, the former USNS Indomitable, had more recently spent time in the hands of NOAA as the McArthur II but had been retired for several years before Triton found it. Despite its dilapidation, several attributes were evident that would make it a strong contender for supporting Caladan's missions:
Selecting the boat that would become the Pressure Drop was only the first battle in a protracted, often exasperating war against the ship's neglected state. Refurbishing and refitting it for Caladan's purposes was "significantly challenging," in Victor's words.
The biggest hurdle was to sufficiently upgrade the ship so that it could be commercially classed—never a concern when the ship was under the auspices of the U.S. government. "Every door in the ship had to be replaced to be fireproof," Victor shares, as one example that contributed to mounting expenses and delays.
Exacerbating the reclassification difficulties was a lack of documentation stemming from the ship's time under operation by a bureaucracy, as lamented by Stu:
"It’s built by the American Navy, so it’s a really weird design. It’s got all sorts of funny quirks that you’d never have. And then it was run by NOAA, who are a great organization, but they probably don’t have the auditability and paperwork that private organizations have, so there’s been lots of modifications that there’s been no documentation on. Just silly things like, you know, you’ll flick a switch and you don’t know what the switch is for. There’s no sign saying what it’s for, and it does nothing in the room you’re in, and you really don’t know what it’s for. At the beginning it took us like six months to just go around and work out what all these switches do. Suddenly someone sat upstairs is saying 'Why are the lights going on and off all the time?' It’s just someone three decks down and around the corner flicking a switch, going, 'What’s this for?' It was things like that."
The saga of the ship's rebirth included transiting the Panama Canal on the way to a dry dock in Mississippi, a complete change in crew, and a final pit stop in Florida at the Triton headquarters to build an on-board hangar for the submersible and to replace all of the communications equipment. Considerably over budget and behind schedule, the Pressure Drop was finally deemed ready for the demanding voyage ahead.
"Any ship can work, it's just a question of time and money," Victor says, when reflecting on the ordeal. There are faster ships out there, for instance, or ones with a higher-rated crane apparatus that would make deploying the Limiting Factor and retrieving it appreciably simpler. As frustrating as the Pressure Drop's cost overruns turned out to be, though, it still cost far less than, say, a fancier research-specific yacht. At the same time, she offered unmatched fuel efficiency, the aforementioned quietness, and a hull whose dimensions happened to easily integrate the sonar device.
In the end, adds Victor, "She turned out to be the perfect ship for us."
Everyone who served on her for any amount of time is incredibly fond of the old girl. She does what she's designed to do very well. —Stu Buckle
The Limiting Factor is retrieved by the Pressure Drop at the end of a dive.
[The landers] were the unsung heroes of the expedition. —Victor Vescovo
While the Limiting Factor makes the headlines and hogs the limelight, three of its deep-diving brethren toil away, tirelessly doing work that is essential for the success of Caladan's missions.
These are the unmanned seafloor landers, named Flere, Skaff, and Closp, after characters from science fiction author Iain Banks' Culture series. Custom-built under the direction of Caladan's lead scientist, Dr. Alan Jamieson, they have enabled an enormous amount of flexibility in gathering data and making discoveries.
A snippet of video recorded by one of the landers while using bait to attract wildlife in the Mariana Trench.
For one thing, the landers can make more frequent dives, without the burden of having to keep a human being alive in some of the most extreme conditions on Earth—a human that will spend around a dozen exhausting hours reaching the seafloor in the Limiting Factor and returning to the surface. They can also swiftly descend to verify depth estimates without having to expend an entire day's manned dive, and they can stay underwater longer. Equipped with high-definition cameras and baited traps, they have been responsible for a significant proportion of the scientific research that Caladan has accomplished.
Beyond those more obvious uses, the landers also serve a critical navigation and mapping function. Follow along in the 3d scene below as Victor describes how the landers were utilized as "acoustic GPS" beacons to help send the Limiting Factor to the right places:
Another advantage of the landers is their ability to be positioned vertically in a way that the Limiting Factor cannot. The reason this matters is that they are then able to collect a wide range of so-called water column data using an instrument called a CTD. The CTD measures Conductivity (salinity), Temperature, and Depth at a given underwater altitude. For the Ring of Fire 2020 expedition, there were two CTDs on each lander, in addition to three that were on the Limiting Factor.
One immediate use of CTD data is to enhance locational accuracy by allowing Victor's aforementioned "acoustic GPS" to account for discrepancies in the geometry caused by variations in water column attributes at differing depths.
Beyond that, though, its measurements can be compared to parallel data from spots in the ocean all over the world. This paints a much broader scientific picture of the characteristics of the ocean and how they may be changing over time. Dr. Jamieson points out how the unprecedented quantity of such water data, all observed by the same instruments, accrued in a relatively short time span, across such a geographic diversity, can provide a reliable reference baseline for future oceanographic studies.
The scientific lander Flere departs before dawn for another day of work in the deep sea.
It's likely that you've seen a world map depicting seafloor terrain. The trailblazing mid-20th century cartographic work by geologist Marie Tharp and her partner, Bruce Heezen, was first rendered artistically for a wider audience in the late 1970s. Since then, such maps have become ubiquitous on classroom walls and in the pages of National Geographic.
A 1977 depiction of the Heezen-Tharp map by artist Heinrich Berann. Source: Library of Congress
As eye-catching as they are, these kinds of maps, warns Caladan's sonar operator Cassie Bongiovanni, are in fact highly misleading, because huge portions of them are still effectively educated guesswork. The truth is that over three quarters of the planet's seafloor has not been mapped to a meaningful degree of accuracy and detail.
This became painfully apparent to Victor and his team during early preparations for the Five Deeps expedition when they realized they didn't know with total certainty where the deepest points in four of the five oceans actually were. Thus the acquisition of a state-of-the-art sonar system—and experts who knew how to run it—became a necessity.
The state of seafloor mapping
Before describing the groundbreaking advances in seafloor mapping made by Caladan and its sonar equipment and team, it's important to understand exactly why our undersea cartography has been so spotty. A good place to start is with the basics: What is sonar, and how does it work?
No matter how good your equipment and personnel are, though, using multibeam sonar to map the seafloor has run into extrinsic limitations, as Cassie explains:
"When you go out and map, you have to pay a lot of money to get the ship time, the fuel, the people, the fuel, the computational power, the system itself, all of that plays into it. And even though there are estimates that say we could get it all done in ten years with ten ships that are dedicated to it, for like ten million dollars or something, I don’t know, something ridiculous. There are estimates out there that estimate the cost and how efficient we could be, but it’s just no one’s really dedicated to it yet."
Through altimetry—the reading of gravitational effects of the ocean floor on its surface—satellites are used to estimate ocean depths around the world.
In the absence of a global effort to obtain high resolution bathymetry, the status quo of our knowledge of seafloor terrain relies heavily on satellites, ironically enough. In the 1990s, scientists realized that satellites were observing gravitational reflections of the seafloor in the surface of the ocean and that these reflections could be used to approximate depth readings.
A depression in the seafloor registers as a dip in the ocean surface, and vice versa for undersea ridges and other protrusions, as illustrated in the accompanying graphic. Though the naked human eye perceives the ocean surface to be essentially flat, these gravity-induced fluctuations are observed and recorded by satellites. This process is referred to as altimetry.
Satellite altimetry, however, runs into struggles with accuracy given its relatively low resolution (roughly producing only one data point per 500 to 5,000 meters, compared to every 100 to 200 meters for the Pressure Drop's multibeam sonar). Altimetry is also susceptible to being deceived by changes in density on or under the seafloor. A boulder or a salt pocket, for instance, can convince a satellite that the ocean is deeper or shallower at a particular spot than it actually is.
We've got satellite altimetry, or a giant blank map...I really think we should just remove satellite altimetry from the maps. It gives people a false sense of completion. —Cassie Bongiovanni
Filling in the holes
Naturally, Victor opted for the most advanced sonar system that was available for purchase. The vendor, Kongsberg, has been a leading name in the maritime technology industry for generations, but its latest multibeam model, the EM 124, had yet to be battle tested. In another show of private investment muscle, Victor forged ahead with the brand new sonar and hired a British debugger to get its software running smoothly.
The most tangible leap that the EM 124 boasted over the previous edition, the EM 122, was a doubling of the number of pings it could emit at once, up to 512. However, Cassie argues that an even more important upgrade was in the computing power of the sonar's back-end software to process out data "noise" and thus produce an even higher quality output.
The numerous CTDs mentioned above that are attached to the Limiting Factor and the scientific landers also play a role in enhancing the quality of Caladan's bathymetric observations. The water column data collected by the CTDs can be used to devise more accurate sound-speed estimates that can in turn be factored into the sonar's algorithms when determining the depth of the seafloor.
Still, Cassie is quick to point out that even with the most state-of-the-art equipment and ample will and resources, human judgment in running the sonar is a significant factor in its effectiveness. Several crucial determinations go into setting up a bathymetric mapping survey.
In the end, between the Five Deeps and Ring of Fire 2020 expeditions, Caladan was able to obtain over one million square kilometers of seafloor bathymetry. Much of the territory covered had never been mapped in high resolution before, if at all. Caladan has freely contributed its data to organizations such as NOAA and efforts such as Seabed 2030 , an international initiative to map the entirety of the world's oceans in high resolution by the year 2030.
One example of an area where Caldan amassed completely new bathymetric data is the Aleutian Trench, running parallel to the Alaskan chain of islands bearing the same name. The swipe block below, depicting a portion of the Aleutian Trench, presents a direct comparison between the GEBCO data as it existed prior to the Ring of Fire 2020 expedition—almost entirely based on satellite altimetry (left)—and the high-resolution bathymetry that was collected by the Pressure Drop (right).
Use the slider bar to contrast the two sets of data as you pan and zoom around the map; note the much sharper and more detailed contours in Caladan's data, and even some underwater features suggested by the previous GEBCO data that turned out not to exist at all! Click on a contour line to see its depth.
This story has only scratched the surface of what makes these technologies so special; to go much deeper requires a whole lot more time and, in some cases, expertise.
What is clear, though, is that each of these components had to not only rise to the occasion on its own, but also had to work in symbiosis with the others. Had any one of them been even marginally neglected or otherwise failed to fit the bill, Caladan's missions would not have been nearly as successful in terms of establishing a new standard for deep-sea exploration. Thanks in no small part to these technologies, Caladan has laid the foundation for future scientific studies of these once-ignored parts of our planet.
A collage of the technology that the Caladan Oceanic team used to make history in action.
The final installment in "The Deep" series will follow the Pressure Drop as it circumnavigated the globe in 2020 and tell the stories of its fascinating discoveries. Follow @ArcGISStoryMaps on Twitter to be the first to know when the next chapter is available!