By: Rhonda Moniz And Kira Coley

The world’s oceans are hectic with advanced underwater technology striving to uncover its longretained secrets. Yet, 60 years ago Denise was the only one of her kind. Developed by JacquesYves Cousteau and engineer Jean Mollard in 1959 at the French Centre for Undersea Research, Denise, or SP350, was the first manned underwater vehicle designed expressly for scientific exploration. In 1965, the advancement of technology allowed Denise, along with Cousteau's team on board Calypso, to explore depths down to 500 m and complete over 1,500 dives. Six decades later, some question if there is still a place for manned underwater systems in scientific exploration and what the future holds for this technology.

Autonomous technology now dominates ocean science due to the recent boom in advanced capabilities, which has opened new applications not possible in the past, such as exploring the waters beneath the Arctic and Antarctic ice, as well as the adoption of Remotely Operated Vehicles (ROVs) in the offshore oil and gas industry. As a result, many manned submersible programs have lost funding, but experts say human-operated vehicles still have a place in ocean science.

Carme Parareda, co-founder, administrator, and chief operating officer at ICTINEU Submarine SL, says that while unmanned vehicles are trending, manned subs still do a good job, “Not only the big systems such as Alvin and Shinkai 6500, but also Curasub, Undersea Hunter, Pisces IV and V, Deep Rover, and Jago have been involved in much science over recent years, to mention only some. But as operators, we see that many researchers are still skeptical about manned submersibles and regard these vehicles as something from the past—old fashioned with few capabilities. That is, until they try them and get enthusiastic about them.”

Parareda says that the first scientific community to use manned submersibles were geologists. With the discovery of hydrothermal vents, the number of biologists in submersibles increased. In the last few decades, archaeologists have been some of the most active.

“Archaeologists appreciated the accuracy of manned submersibles in their delicate work,” Parareda says. “Biologists are aware that they will be able to see much more from a submersible than through a camera attached to an ROV. Geologists know that even with a few dives down to the seafloor, the 3D vision and perception they will have offers a clearer and faster understanding of the geological structures, including the seafloor, seamounts, and chimneys.”

Dr. Adam Soule, chief scientist for Deep Submergence at the Woods Hole Oceanographic Institution (WHOI) agrees, "Having a human presence in the deep sea is irreplaceable. The ability for humans to quickly and efficiently process the inherently 3D world around them allows for really efficient operations and excellent sampling potential. Besides, there is no better experience for inspiring young scientists and for ensuring that any scientist can get the most out of unmanned systems than immersing themselves in the environment.”

HURL's Pisces submersible being launched from research vessel.

HURL's Pisces submersible being launched from research vessel.


HURL's Story

One organization whose history illustrates this evolution from manned to unmanned submersibles is the Hawaii Undersea Research Laboratory (HURL). Beginning in 1981, the program utilized the manned submersible Makali'i, which made the first dive to conduct studies in the crater made by the first hydrogen bomb tested: the Oak Crater in Eniwetak Atoll. HURL conducted three months of diving operations at Eniwetak Atoll, and the expedition launched HURL as a science diving program.

In 1986, HURL acquired the manned submersible Pisces V and in 2000, the Pisces IV was acquired from the Canadian Navy. The two Pisces submersibles have worked in tandem and are considered shallow water subs with a maximum depth of 2,000 m. They were designed for the oil and gas industry and originally used for communications cable surveys and cable burial works, each sub was built with skids that keep the belly pan off the bottom. When doing cable burial work, the subs would straddle the cable and move over the cable with a water jet to form a trench to bury the cable.

HURL's Pisces submersible investigates wreck off Pacific atoll.

HURL's Pisces submersible investigates wreck off Pacific atoll.


In 2005, the team conducted a five-month expedition to explore 13 active volcanoes from Samoa to New Zealand. In total, 56 dives were planned and the HURL team was able to get in 63 dives despite some challenging weather.

“We encounter more entanglement issues in a dive season than most deep diving subs will encounter in a whole career. So, having two submersibles not only gives us immediate backup capabilities, but it really doubles the productivity. We are really diving the buddy system with two subs on the bottom. They are both really unique in operations. There are some areas where certain assets are more suitable than others,” said Terry Kerby, director of submersible operations at HURL.

In an industry that has seen a trend toward more autonomy and remotely operated systems, manned submersibles face challenges. NOAA announced the discontinuation of funding for Pisces operation in 2012. The crew turned to a smaller footprint for operations.

“We reactivated the LRT-30a and by the end of 2012 it was re-certified by ABS and a new crew of divers and pilots were trained. We chartered a 75-ft tugboat, the American Emerald, to support LRT-30a and Pisces V science dives. We were able to pull off a flawless threemonth science dive season. There are some areas where certain assets are more suitable than others. You can dive on an atoll that may come up hundreds of meters right up to a breaking fringe reef. So if you are trying to dive with a tethered vehicle you practically have to park your support ship on the reef to get a vehicle down in this really rugged terrain. With the Pisces, we can come right up to SCUBA diving depths. You can come up as shallow as you want until you start to feel the surge.”

Bruce Strickrott and Susan Humphris inside the Alvin sphere. Photo credit: Chris Linder, Copyright © Woods Hole Oceanographic Institution

Bruce Strickrott and Susan Humphris inside the Alvin sphere. Photo credit: Chris Linder, Copyright © Woods Hole Oceanographic Institution


The roller coaster ride continued when in 2014 all science proposal requests to NOAA for Pisces operations were rejected. The team managed to pull together several film documentary dives, but in 2015 operations were scheduled to be discontinued once again, until the Chinese came through with a prospect for a two-month expedition in the South China Sea scheduled for early 2016. In preparation for the expedition, the submersible completed recertification and test dives. Prior to departure for the South China Sea, the project was canceled due to political tensions between the U.S. and China over some of the regions where the Pisces submersible would be diving. The University of Hawaii had incurred considerable costs to prepare the ship and submersibles and the expedition was lost without compensation for the costly upgrades. Once again, the program was in danger of being shut down. Thankfully, the reactivation of the LRT-30a in 2013 had caught the attention of the U.S. Navy's Special Operations Command, which led to a contract with the Navy to train SOCOM divers to pilot the LRT and kept the HURL operations team intact for a few more months.

The Navy work gave the team time to put together some dives with Dr. Sylvia Earle and National Geographic. Several NOAA coral dives followed with three days of seamount exploration and Loihi dives with Greg Stone and Conservation International, during which HURL/KOK operations conducted 18 dives in 10 days in spite of two passing hurricanes.

The team was a day away from moving the submersibles back to Makai Pier when the Pisces were contracted to conduct National Science Foundation (NSF)-funded deep coral research dives in the Northwestern Hawaiian Islands and beyond. The KOK and Pisces submersibles went out in late October for 30 days of dives on five different seamounts and were able to complete 12 days of 14 scheduled dive days before the team was chased out of the area by a typhoon. As of now, the Pisces subs are scheduled to complete the Northwestern Hawaiian Islands deep coral dives in 2017, which will keep the capability intact a little longer.

“ Many researchers are still skeptical about manned submersibles and regard these vehicles as something from the past . . . That is, > until they try them.”  – Carme Parareda


A New Generation

“Concern about daily operating cost is far greater than in the past, and engineers search for alternatives to the big ROVs systems,” says ICTINEU's Parareda. “The alternative is vehicles without umbilicals, but if you don't put a human inside—in most cases to date—you still have the risk of losing the vehicle. As a result, the manned submersible is the safest technology available at the moment. In terms of time underwater, ROVs and AUVs are unbeatable. But with the ICTINEU 3, for example, you may run two 10-hr dives, charge batteries for 4 hrs, and go back to sea, which approaches to an ROV's productivity.”

Manned submersibles have a safety advantage over tethered vehicles when working around complex submerged platforms where entanglement issues can be a problem.

In 2004, ICTINEU Submarine sought to develop a new generation of manned submersibles. Since that time, the technology has advanced enormously, creating a significant gap in depth rating and a need for numerous modifications to meet the demands of 21st-century science. According to Parareda, “Research submersibles used to be heavy machines weighing between 10 and 20 Tm for depths deeper than 1, 000 m. This meant they need large oceanographic vessels and cranes to be deployed—similar to larger ROVs. There was a need for weight reduction if we wanted to make a manned submersible easy to operate, easy to deploy, and affordable for the scientific community. The ICTINEU 3 weighs only 5.5 Tm, carrying three people in a 1,200-m rated vehicle.”

“There was also a huge gap in energy technologies. We have seen an evolution of batteries from lead-acid to nickel- cadmium to the latest generation high-density lithium batteries, with many others in between—and, in parallel, energy systems such as fuel cell appeared as alternatives. Only some teams had risked with lithium-polymer batteries in experimental vehicles, but nobody had thought about a high density-high power system, pressure- compensated in a manned vehicle. So, after many years of engineering and testing, we came across a system that has five times more energy than most submersibles with same or even less volume and weight.”

The ICTINEU team has also worked on vehicle hydrodynamics, resulting in improved safety, better underwater navigation and piloting, and low energy consumption. A development they want to implement on submersibles is a smart piloting assisted system, similar to the ones used in aerospace.

“We have seen the WHOI Alvin having been completely refitted and given new capabilities recently. The Chinese submersible Jiaolong is a newly built vehicle and they are working on a new full-ocean depth vehicle and several 2,000-m vehicles. Thanks to a robust battery system, our ICTINEU 3 can run up to 40 km underwater or upload as many equipment and tools as needed without reducing the mission time,” states Parareda.



The Woods Hole Oceanographic Institution's (WHOI) Human Occupied Vehicle (HOV) program faces challenges as well, in spite of the fame of its flagship. Commissioned by the Navy in 1964, Alvin was one of the world's first deep-ocean submersibles. In the mid to late 1960s, Alvin was selected to attempt the recovery of an H-bomb that dropped when an Air Force B52 collided with a tanker in the Mediterranean. The following year, Alvin returned to the Bahamas to collect biological and geological data. In the 1970s, the sub worked off Martha's Vineyard, the Mid-Atlantic Ridge, and many other locations in the U.S. and abroad.

In 1986, the Alvin group, along with WHOI's Deep Submergence Lab (DSL), set their sights on the famous wreck found by Dr. Robert Ballard: the RMS Titanic. The shipwreck had not been seen in 75 years. The team made several dives collecting video footage, the same footage that audiences would see 12 years later in the opening scene of the blockbuster hit movie Titanic.

Alvin has had many overhauls over its lifetime and, as a result, it has remained state-of-the-art. Currently, Alvin is rated to 4,500 m, giving scientists access to two thirds of the ocean floor, and plans are in place to increase the vehicle's maximum depth to 6,500 m, making it one of less than a dozen vehicles on earth currently being used outside of the military that can reach the deepest depths of the Hadal zone.

Manned Submersibles and Citizen Science The rise of citizen science has fueled an increased interest in manned submersibles, but there is some debate about the use of manned systems for this purpose.

Photo courtesy of P. Gregg (U. Illinois), D. Fornari (WHOI), M. Perfit (U. Florida)/NSF/WHOI-MISO Facility ©2016 Woods Hole Oceanographic Institution. Cochief scientists of OASIS cruise AT37-05 on RV Atlantis funded by the National Science Foundation.Images and video taken from DSV Alvin on Dive 4850 (Nov. 17, 2016) on Matthew Seamount in the 8° 20'N Seamount Chain in the eastern equatorial Pacific using WHOI MISO Facility deep-sea camera systems ( P. Hickey was the Alvin pilot on Dive 4850. © Woods Hole Oceanographic Institution (WHOI).

Photo courtesy of P. Gregg (U. Illinois), D. Fornari (WHOI), M. Perfit (U. Florida)/NSF/WHOI-MISO Facility ©2016 Woods Hole Oceanographic Institution. Cochief scientists of OASIS cruise AT37-05 on RV Atlantis funded by the National Science Foundation.Images and video taken from DSV Alvin on Dive 4850 (Nov. 17, 2016) on Matthew Seamount in the 8° 20'N Seamount Chain in the eastern equatorial Pacific using WHOI MISO Facility deep-sea camera systems ( P. Hickey was the Alvin pilot on Dive 4850. © Woods Hole Oceanographic Institution (WHOI).


“Manned submersibles, as currently constituted, are not ideal tools for citizen science given that they are designed to get experts into the environment they are studying,” suggests WHOI's Soule. “However, there is progress towards democratizing that experience by, for example, enabling acoustic communications of text and images from sub to ship and the reverse. Alvin has recently implemented an acoustic comms package for this purpose. As this technology develops, the notion of bringing more citizens into the submarine .virtually' becomes viable.”

Stern view of Alvin being deployed on dive AL4685

Stern view of Alvin being deployed on dive AL4685. Photo credit: Chris Linder, © Woods Hole Oceanographic Institution (WHOI).


The Human Element

The director and senior pilot of the WHOI's HOV program, Bruce Strickrott, believes manned vehicles still have a role to play: “I think they work well with other tools. It's just like the push to go to Mars. We have plenty of tools roaming around Mars that are giving us data, but it is also clear to me that there is this great desire to go there. I think it is for the same reason. We will never truly know a place until we visit it. You can get to know a place through study and through various means and various tools, but until you actually go there, your full understanding is not there. Your perspective is not complete. Manned vehicles provide that opportunity. A manned vehicle allows you to take your imagination down to a place and see it and bring it back with you. It provides that extra piece to the puzzle of understanding.”

Parareda suggests that the human element of the manned submersible is key. “Why isn't the public as motivated about Mars exploration as they were during the mission to the moon? Maybe it's due to human presence. Take people to Mars and, once again, you'll have millions of people staring at the TV. The same happens with the sea: children, but also adults, get extremely excited about subs. There is an evocation to adventure, to the unknown, and this must be used to raise awareness. ROVs do not have such power.”

Soule adds, “There is no replacement for bringing humans into the environment they are studying. Rather than pitting manned and unmanned technologies against each other, scientific fields should recognize the powerful synergies created when these technologies are used together.”

"I believe that keeping manned submersibles in our arsenal of tools to investigate the deep ocean —alongside autonomous and unmanned vehicles —gives us the greatest opportunity to learn as much as possible about the deep ocean. Having access to manned systems has been central to the development of my understanding of the deep ocean. As a geologist, I learned my craft by immersing myself in the environment, standing on the outcrop, walking over the terrain, handling the rocks. To be denied that in the deep ocean makes it nearly impossible to gain the same depth of understanding. Manned submersibles restore that ability to deep sea scientists—be they geologists, biologists, chemists—and enables them to develop richer interpretations of the data generated by unmanned systems,” concludes Soule.

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