Scientists at the Hawaii Undersea Research Lab like to do things in person, even if that means diving a mile beneath the ocean near an active volcano.
The lab, formed in 1980, is the only U.S. facility in the Pacific equipped with submersibles used for scientific observation, sampling and exploration.
“It was part of a national initiative to put people in the sea,” said John Smith, science director of the Hawaii Undersea Research Lab.
Scientists use the subs to track deep-water species and examine ocean chemistry and thermal events. They even discovered a Japanese mini sub that took the first U.S. fire in the Pacific in World War II.
The lab’s submersibles were castoffs originally used to inspect deep ocean oil pipelines “At the time, ROVs were in their infancy and manned submersibles were what were mostly used,” Smith said.
Now they’re fully rebuilt and equipped for deep sea observation, sampling and exploration. All that remains from the original subs are the 7 foot steel spheres where the three person crew rides safe from cold, high-pressure water.
The Pisces IV and Pisces V are equipped with a wide array of tools for undersea research. That includes conductivity temperature depth sensors, core samplers, sediment samplers, rosettes, sonar, high-quality cameras and even milk crates to bring large samples to the surface.
Smith said the submersibles give researchers the opportunity to observe the environment in person, which is a valuable resource. Species identification is much easier through one of the submersibles six-inch-thick windows compared to ROV video.
Deep-water ROVs are also harder to work with because they are tethered to a ship, which limits travel and raises the possibility of entanglement.
“It’s harder to change your mind with where you want to go because of a large cable,” Smith said. “It’s harder to move the whole ship and the whole configuration.”
And what’s it like to pilot a small sub in the deep ocean?
“Well, you don’t want to be claustrophobic,“ Smith said.
Two riders, a pilot and all of the necessary controls are confined to a 7-foot sphere. Riders lie prone and look through the view ports. Bioluminescent particles sparkle in the dark as the subs descend through the water column.
“It’s kind of like a fireworks show,” Smith said.
The deepest water where the submersible travels is just above freezing and there’s no heater. The sub gets down to about 50 degrees Fahrenheit, but riders bundle-up.
“It gets kind of damp in there because you get condensation in the sphere,” Smith said. “When you are in there without rest or movement for eight hours and it gets kind of damp, it gets pretty cold.”
Riderless ROVs can outlast a manned submersible beneath the sea because they don’t have to account for oxygen supplies and rider fatigue.
Failure of ROV technology also doesn’t threaten lives. Catastrophic failure in a manned submersible more than a mile beneath the ocean’s surface, may be perilous for riders.
The lab’s dives have never had a major problem. Smith said diving conservatively and always having a backup is the best policy. “If things aren’t looking good you leave the bottom right away,” Smith said.
Navigating around underwater structures like shipwrecks can pose a threat to a dive. “The biggest problem that pilots will tell you is entanglement,” Smith said. “That can be a big issue.”
Another issue the lab faces is where to store all of their data. Smith said they generate about 10 terabytes per year. A new server system donated to the lab by Intel and HP with 200 terabytes of storage will help researchers store their information all in one place.
That information includes recordings of geology in action off the coast of Hawaii’s Big Island. On a growing Lo’ihi Seamount, an active volcano spews out magma building what will one day be another Hawaiian Island, Smith said.
There’s also footage of training dives that led to the 2002 discovery of the first enemy fired upon by the U.S. in World War II.
A green crew on the USS Ward Naval Destroyer fired upon a Japanese sub the morning of the Pearl Harbor bombing. The mini subs were sent out ahead of the bombers to torpedo American ships. Smith said no one believed that the crew sunk the sub.
“That year we found it and it had the hole measuring the cannon size they used,” Smith said.