Beneath the Surface

Going deep with the Park Service's Submerged Resources Center

By Ian Shive

High winds stir the cobalt blue waters of Lake Mohave, turning it into a pot of water at full boil. But the two lead underwater archaeologists on the National Parks Submerged Resources Center (SRC) team don’t much care about what’s happening on the surface. They’re too focused on what lies beneath: the possibility of a new discovery, like gold-mining equipment that plumbed the depths of the Colorado River long before the Hoover Dam was constructed, or an entire town, abandoned before Lake Mead’s rising waters erased it from the landscape. Or it might just be another day alone in the quiet abyss with seldom a fish in view.

Experts at diving in almost any conditions, Sami Seeb and David Choate start their day by donning full-body fleece, the first line of defense against the dangerously cold 55-degree temperatures. Thick, airtight dry suits provide their outer defense, completely sealing off their bodies from the frigid waters while allowing a thin warm layer of air to keep them comfortable even in the coldest and darkest depths of the lake. The high-tech suits, which require special dive certification, are sophisticated pieces of gear modeled on the modern-day astronauts’ space suit.

Choate and Seeb, the lone female diver on this trip, direct a team of seven other professional divers who will spend six intense weeks in southern Nevada, surveying and studying the underwater resources of both Lake Mead and Lake Mohave, both part of Lake Mead National Recreation Area. It’s a job that many people would kill for. “I get to dive in some of the coolest places in the country, and my office is the national parks. How great is that?” asks Seeb, knowing the answer full well. But as Choate points out, the best part of this job is also the worst—being away from home for weeks on end. For this project, the entire crew will live aboard floating houseboats, with 1980s-era interiors decked out for retired tourists and families spending a few nights on the lake, not for state-of-the-art science. A few of these elite divers even joke about entering the lake via the houseboat’s water slide. But the vessels are roomy enough to get the job done and give everyone a little elbow room, and that’s all that matters.

As four-foot swells toss the boat in every direction, one diver gives a thumbs-down signal. It’s not an indication of distress but diver sign language for “time to make our descent.” As the divers quietly slip into the murky depths, the first bubbles from their life-support systems begin to drift upward. The duo slowly follows a previously set guideline that will steer them 60 feet to the bottom, where a scene of destruction begins to emerge. In repose on the lake bottom, twisted steel mingles with a plethora of other debris and sea life. To the average diver, this site wouldn’t prompt a glance, but Seeb’s background in maritime history helps her identify the final resting place of a massive gold dredge that fell into these waters nearly a century ago. The large mechanical structure acted like a giant gold pan, sifting dirt and soil with water and revealing pieces of gold that were plentiful at the turn of the 20th century.

During the next several days, members of the team will visit the dredge over and over again to catalog every inch of its 100 feet. Each time they dive, they will plot points, record details, take photographs and video, and interpret the historical significance of their find. During its six weeks on these lakes, the team will document dozens of sites with the goal of adding some of them to the National Register of Historic Places, creating interpretive signs and maps for park visitors, and ultimately, opening the sites to recreational divers.

Before any of that can happen, however, the team’s members will spend hours discussing their observations from earlier in the day. As they crowd around a single video monitor to watch footage from one of the other team members, they hope to identify some new revelation about the wreckage. In addition to earning master dive certification and completing a rigorous Park Service dive-training program, many of the members have pursued advanced studies in maritime history and marine biology, a key element of their profession.

And sometimes, even that isn’t enough. In this case, the SRC team needs to intimately understand the inner workings of machinery that hasn’t been manufactured in a century. Seeb finds it useful to pull old black-and-white photos from the National Archives to help identify what she might be looking at underwater. As she talks about how a 1909 gold dredge operates, she speaks with the speed, enthusiasm, and authority that you might expect from the person who constructed the dredge 100 years ago.

The Submerged Resources Center has had many incarnations since its inception in 1975. Founded by Daniel Lenihan, who retired in 2000 but still plays an active role, the team is based in Santa Fe, New Mexico. This landlocked state isn’t the first place you would expect to find an elite team of divers, but the center has been there ever since the Reservoir Inundation Study, when water shortages surfaced as an issue in the American West, and conflicts over water rights began soon thereafter. The SRC was asked to investigate the issues and take a close look at the impact that human-made structures like the Hoover Dam have on natural and cultural resources. As the study came to a close, other needs arose, including the assessment and study of the USS Arizona at Pearl Harbor; Lenihan was happy to step in.

Originally from New York City, Lenihan started working with the Park Service in 1972 while attending graduate courses in anthropology at Florida State University. An avid diver, he especially enjoyed the technical demands of investigating caves and shipwrecks. In 1974, he headed west for the Reservoir Inundation Study and began building his team. Over the next 30 years, the SRC would eventually operate throughout dozens of national parks, in U.S.-owned properties in other countries, and in areas where it had an archaeological or historical interest, such as the English Channel, the North Sea, and Micronesia.

One of the greatest successes, and one of the most difficult projects from a public relations standpoint, was the SRC’s work on Bikini Atoll in the Marshall Islands, where the United States conducted nuclear testing during World War II. In this Pacific Island paradise, A-bombs were dropped on ships throughout the atoll, leaving a trail of wreckage at the sea floor. Decades after the testing, the government wasn’t sure what to do with the site, so officials asked the SRC to conduct an assessment. From 1989 to 1990, the team mapped all the vessels, using state-of-the-art science, and concluded that the site posed no radiation risk. It also made the decision to open the shipwrecks to the dive community in 1996.

At the time, the public’s perception of a nuclear site was much like the view of Chernobyl—it’s never safe to return. This false perception turned into negative media coverage, and the SRC unit was in the crosshairs. But as other organizations released their own independent studies declaring the site safe, the dive community began to soften its stance, and eventually the negative reactions went away. Not long after and to this day, the atoll has become a major dive destination.

“Many people in the dive community paint us at the bad guys who are trying to stop diving on historical sites,” says Lenihan, “but in the last 30 years, the only sites where we recommended no access to divers were Pearl Harbor’s USS Arizona [the tomb of more than 900 soldiers] and a historic shipwreck in Biscayne National Park.”

According to Larry Murphy, chief of the SRC, the unit’s primary goal is also its greatest challenge: balancing visitor experience with resource protection. Just like rock climbers gaining access to more remote locations, divers also have access to sites that the average park visitor generally doesn’t see, and their visits can easily damage the resource. Seeb once attended a dive meeting that preceded the establishment of a new site and encountered angry protests about the permitting system put in place. The Park Service mandate—to protect our resources for future generations—requires striking a delicate balance between visitor experience and access limitations that the public often doesn’t understand.

“Visitation to the site needs to be limited so that we can protect it,” says Seeb. Even though it’s the right thing to do, it can be a frustrating decision. “The hardest part of the job is when the visitors—who own these parks—aren’t happy with how the Park Service manages the site,” she says.

In Isle Royale National Park in Lake Superior, Wisconsin, the SRC didn’t stop people from diving on wrecks that were hazardous to reach. The reason: There’s nothing that says you can’t take a risk in a national park. But the SRC believes people need to be informed. As long they don’t damage the site and are made aware of the dangers, they should be granted access.

Dave Conlin, a veteran diver and archaeologist for the team, believes the parks need to further develop relationships with the dive community to communicate more efficiently with potential visitors. “We’ve discovered that there is inevitably more risk in doing nothing than there is in opening a site to divers and properly managing it,” he says.

If anything, the SRC wants to get more people to appreciate these sunken treasures. “If the parks could interpret what they had underwater—through video or images—people would have a better connection to those resources,” says Seeb. But too many parks lack the financial or human resources to get underwater and discover what’s there.

When it’s time to determine just what’s down there, the SRC team is typically called in, and although there is no “wait list,” many national parks could benefit from an underwater survey. Most park visitors don’t realize how many bodies of water there are within the Park System. Even the average, backcountry pond could yield significant historical artifacts from Native American settlements or Paleolithic tools. To set its priorities, SRC staff members discuss which sites require attention and face the greatest threat. For instance, at Lake Mead and Lake Mohave, the extreme drought in the American West has caused water levels to drop more than 80 feet. As a result, sites that were too deep for novice divers are now within reach; the famous B-29 bomber, for example, is now only 140 feet below the surface. As the shorelines recede, other sites are being exposed to the non-dive community for the first time and could be subject to vandalism and theft. This drastic shift in water levels and the potential for damage to natural resources moved Lakes Mead and Mohave up to the top of the SRC list.

The team’s annual budget is less than $400,000, but many of the costs associated with its work are covered by the parks themselves or partner institutions. Because SRC has only seven full-time staff, the role of each team member shifts with the sites, goals, and expertise required on a given project. On some sites, including Lake Mohave, the SRC will look for assistance from dive volunteers. Before volunteers can dive with the Park Service, however, they must complete the same rigorous diving and medical certification required of employees. Sometimes volunteers will act as dive buddies for safety or help transport materials to a dive site. Local divers can also contribute a tremendous amount of knowledge to the team that would otherwise take months, if not years, to gain.

Many of us forget that there are places in our country’s landscape that have an underwater counterpart: Gettysburg Battlefield can be compared with Pearl Harbor, Bryce Canyon’s hoodoos with the Virgin Islands’ coral reefs, and Yellowstone’s wildlife with Biscayne’s marine life. So, while most Americans are reaching for their first cup of coffee in the morning, members of the Submerged Resources Center are out in a small boat, battling currents, and suiting up for a cold-water dive that might help all of us better understand the world just beyond our reach.

Ian Shive is a California-based conservation photographer and writer.

This article appears in the Fall 2008 issue.

National Parks, our award-winning quarterly magazine, is an exclusive benefit of membership in the National Parks Conservation Association. Subscribe today!

Click here to continue reading this issue


Post a Comment

Thoughts about this article? Comments you'd like to share with the editors? Post your comments below* or send an e-mail to, and we'll consider printing your letter in the next issue of National Parks magazine. If you write a letter please include your name, city, and state. Published letters may be edited for length and clarity.

Enter this word:

* Your comments will appear once approved by the moderator. NPCA staff do not regularly respond to postings. We reserve the right to remove comments that include profanity, personal attacks, or are off-topic. Opinions expressed here do not necessarily reflect the position(s) of NPCA. By submitting comments you are giving NPCA permission to reuse your words on our website and print materials.


Want to learn more about the  ?

The   can be seen in the wild in America’s national parks. Why not join the National Parks Conservation Association community to protect and preserve our national parks?

Sign up to protect parks in   & other states

Why not join the National Parks Conservation Association Community to protect and preserve our national parks?

Sign up to protect   and other National Parks

Why not join the National Parks Conservation Association Community to protect and preserve our national parks?

Please leave this field empty
Yes, please sign me up for NPCA’s newsletter and other emails about protecting our national parks!

National Parks Conservation Association
National Parks Conservation Association

Log In

Or log in with your connected Facebook or Twitter account:


Welcome to our growing community of park advocates. Thanks for signing up!

Sign Up:

Or sign up by connecting your Facebook or Twitter account: