Underwater at the USS Arizona

Written by Jessica Keller, archeologist for the NPS Submerged Resources Center

Photos by Brett Seymour, A/V Production Specialist / Deputy Chief for the NPS Submerged Resources Center

 

Gearing up for a dive
Nothing could be more picturesque than gearing up for a dive beneath rainbows arching just behind the USS Arizona Memorial. Each dive in this special place brings new emotions, realizations, and observations.

Most people associate diving in Hawaii with beautiful, clear blue water, but that's not the case in Pearl Harbor. Visibility can be very low due to the suspended sediment in the water column from boat traffic and stream runoff emptying into the harbor. These conditions make the USS Arizona extremely difficult to photograph on a large scale. At times, the ship and features can only be seen in 3-5 foot increments, making viewing or imaging the 608 foot long vessel a daunting challenge. Days with great visibility are not as common, but when they do occur, visibility can be up to 25-30 feet.

 

Life at the USS Arizona

Reduced visibility forces divers to recognize to site features and create a mental map of the ship in their head. It also draws one’s attention to the smaller details that can go unnoticed in other areas where a diver’s range of visibility is wider. For instance, small nudibranchs or sea slugs are tiny creatures ranging in sizes from 0.16 to 23.62 inches. The nudibranchs seen on this site are just over one inch with blue and white spots with red gill plumes. Usually, these tiny creatures remain unseen, but if one’s range of sight is only 3 feet, these small creatures are an exciting find!

In addition to nudibranchs, we have sighted a number of brown seahorses. According to the park, the brown seahorse had not been seen on the site for a few years, but over the past couple of days, we have seen and photographed a number of these delicate animals, including a pregnant male! Seahorses are unique in this aspect as the males carry and give birth to the young.

A surprising amount of other sea life such as sponges, coral, algae, fish, and spotted eagle rays call USS Arizona home. The shallow warm water covering the main deck creates a stable and protected environment for these animals.

 

Sunlight on the ship
Sunlight plays off the bright orange sponges and metal angles of the ship. Dancing across the deck, the sunbeams have mesmerized me numerous times, lighting certain features with a rainbow-like aurora. Though the ship is built out of thick steel, for some reason, the filtering light across the deck makes this place seem fragile, delicate, and even more special.

The sunlight also reflects the droplets of oil still leaking from the ship. Considered the tears of the fallen, the drops of oil percolate out several sections of the deck. The oily sheen stretches across the water, wind-driven towards the damaged bow and out to sea.

 

Oil at the USS Arizona
Astoundingly, an estimated half a million gallons of oil still remain inside the stern of the vessel. The National Park Service is constantly monitoring the condition and status of the leaking oil. As the main steward of USS Arizona, it is the park's responsibility to understand and document the changes and deterioration of the vessel over time.

One of the main objectives of the upcoming ROV internal investigation is to penetrate down into the lower decks to view the state of preservation and condition of the oil compartment walls. Previous ROV investigations over 15 years ago revealed low levels of dissolved oxygen creating an anaerobic environment, which reduces deterioration and corrosion rates. This project hopes to find similar conditions and reveal more of the lower decks. Entanglement and severing the tether limited the previous internal investigation. Unlike the past, this custom ROV built by Marine Imaging Technologies and Woods Hole Oceanographic will lay its own tether, which will allow scientists to explore new and never before seen hallways and rooms. By understanding the unique environments, both inside and outside the vessel, the National Park Service can manage and plan for the next 100 years.

 

The Next 100 Years
Sadly, just as this project is building momentum, my time here at Pearl Harbor is coming to a close. My obligation to another project is carrying me back to the mainland. I am incredibly honored and grateful to have had this exceptional opportunity to work on USS Arizona and share this experience with you. Not only has it been a career highlight and a dream come true, but also an experience that has touched my mind and soul more than I could have ever anticipated.

As the National Park Service turns 100 years old next week, I can say that I am proud to be a member and look forward to what the next 100 will bring!