KAILUA-KONA — It took three dives — one down to where the only light is the stabbing ray of a flashlight or the biolumensce of sea life — to check if the seawater pipes at the National Energy Laboratory of Hawaii Authority are staying put.
Over the weekend, three-person crews from NELHA and the Hawaii Undersea Research Laboratory took dives to make sure the mountings for the pipes remain in good condition, said Jan War, chief operations officer at NELHA.
The pipes themselves are unlikely to develop problems, NELHA Executive Director Greg Barbour said, as some are over an inch thick.
“Leaking is the least of our worries,” he said.
The most massive pipe is the 55 inch pipe, which runs 10,249 feet offshore.
At that depth the Pisces V submersible was brushing on the bathypealgic zone, where the only light present is what’s made by living things or brought by humans.
The rest of the dives were solidly in the Mesopelagic Zone, where light is extremely faint.
The Pisces submersibles, which are used to survey the pipes, are 20 feet long, 10.5 feet wide and 11 feet long and can operate for up to nine hours.
For these dives there were two consistent crew members: pilot Terry Kerby and War. The third position is held by a different NELHA staff member for each dive.
Their vision is limited to what they can see through the portholes with searchlight or video cameras on the hull.
Each dive focused on one of the pipes, starting on Friday with the 55 inch pipe, followed by the 40 inch pipe on Saturday and the 18 inch pipe on Sunday. Sunday was also a survey of the pipes leading into the fish farms, according to the ship’s records.
The dives cover the intake point to to about 300 or 400 feet deep. Getting any closer to shore is unsafe for the submersibiles, Barbour said.
These dives will help ensure the pipes are good for the next 25 years, he said.
The submersiable is launched from the Kaimikai-O-Kanaloa, a 223-feet long ship that can carry up to three submersibles. For these dives they are carrying two submersibles. The Pisces V did the survey, while the Pisces IV was a backup, according to the vessel’s logs.
HURL is based out of the University of Hawaii at Manoa and is operated in conjunction with NOAA. Their discoveries have included the Japanese two-man submarine sunk by the destroyer USS Ward on Dec. 7, 1941, along with several other submarines sunk in the area. They also perform research dives for scientists studying reef development, volcanoes and deep-sea ecosystems.
NELHA arranged this inspection off one of those journeys, when the ship was headed to port from a scientific dive on the submerged island of Loihi on Thursday, said Barbour.