Nuclear Scuba:

Advanced Training Offered in a Texas Missile Silo

Story by David Prichard, photos by Lily Mak

Depending on where you are, you're likely to hear dive sites described as "cool," "hot," "radical," "stellar" or "awesome." Deep in the heart of Texas sits the world's largest indoor deep-diving training facility — a site that could easily be described as "nuclear." Constructed with about 7,847 cubic yards (5,964 cubic m) of concrete and 1,288 tons (1,159 m tons) of steel reinforcements, this 60-foot- (18-m-) wide cylindrical "pool" drops to a depth of 127 feet (38 m) with nearly 2 million gallons (7.6 million liters) of clear water in which to dive. And, by the way, the facility used to house a nuclear-tipped Atlas missile.

For the past 10 years, divers have been getting advanced training in this flooded former missile silo with the majority of the certifications covering deep, night, altitude, rescue, mixed-gas and rebreather specialties. Dive Valhalla, which gets its name from Norse mythology, is not conducive to open-water training, say owners Mark and Linda Hannifin of Family Scuba Center in Midland, Texas, but does allow for a unique setting to conduct training for many technical skills in a controlled environment.

"In deep training, nitrogen narcosis can become a factor. This site makes it easy for instructors to monitor students without losing sight of anybody," Mark Hannifin said. "The water is nice and clear, so it's less intimidating on the students than being in a lake where you can't see the surface light at depth."

Twenty miles (32 km) southwest of Abilene, Texas, the converted missile silo has had numerous dive stores contact the Hannifins to arrange weekends for class sessions, yet only about 300 divers have dived the silo over the past decade. "It's a unique experience and you have to be a bit adventurous to want to dive it," said Hannifin. "I don't know where else you can dive a missile silo."

It's a Long Way Down

Getting from the entrance on the surface to the silo's diver staging area requires divers to haul their gear down five flights of stairs, through two corridors that are flanked by large blast doors and into a large room that once housed the silo's control center and living area. After gearing up, divers then walk through another corridor to an opening in the silo 25 feet (7.5 m) above the water's surface and about 45 feet (14 m) below the silo's launch doors. A recently constructed stairway extends from the opening down 33 feet (10 m) to a floating dive platform where divers make last-minute gear adjustments before taking a giant stride into the water. To help divers get back on the platform, a mounting ladder from a T-38 airplane was added. Hannifin said the airplane's name was "Echo," which is etched on the ladder. The title is appropriate for this cavernous setting.

Up until a few years ago, before the floating platform and stairway were added, divers had to climb 25 feet (7.5 m) down (and back up) on a pair of extension ladders that were chained together, while their gear was lowered
to them by rope as they floated in the water. Hannifin and his friends later bracketed the ladder to the wall and added a winch to lower and raise the gear. Now divers can easily walk down the staircase wearing their gear. Additional lighting throughout the structure and especially in the silo has given it a brighter appearance with ambient light reaching down to at least 60 feet (18 m) underwater. Additional amenities, like bench seating in the staging room and an indoor bathroom, have also been added recently.

The constant air and water temperatures (68-degree-Fahrenheit [20-degree-Celsius] air and 60-F [16-C] water) in the silo allow for controlled diving, while on the outside, Texas' summer temperatures can average over 100 F (38 C) and winter months can be below freezing. "The divers here in Texas think 60 degrees is pretty cold, but we've had other divers from California and Alaska that think it's pretty nice," Hannifin said. "It just depends upon your perspective."

The constant environmental conditions and clear water were key factors in choosing the silo as the site for a freediving clinic this summer by record holder Tanya Streeter. Hannifin said the clinic's emphasis was on freediving techniques within a range of only 50-70 feet (15-21 m) so the silo's ample depth and clear water made it much more attractive than holding it in a lake that had little visibility and numerous thermoclines. These factors also contribute to why instructors like to conduct technical training here. At 2,420 feet above sea level, the site has the distinction of being a place where you can dive underground to get an altitude certification.

A Little History

The site itself started back in the early 1960s when the U.S. government built a series of ICBM (intercontinental ballistic missile) silos around Abilene to act as part of our MAD (mutually assured destruction) deterrent during the Cold War. Only two years after it was finished, the silo became obsolete and was decommissioned; the Atlas missiles were modified to launch Mercury astronauts and satellites into space. After its contents were sold for salvage, the silo was left to fill up with groundwater.

The Hannifins found the silo with 11 acres (4.5 hectares) of land for sale in a newspaper ad while traveling through Abilene. Curiosity got the best of them. "I'd never seen a missile silo before," Hannifin said. The couple arranged to see the silo with the owner and offered him a "low-ball" figure for the site. The Hannifins were surprised when the owner accepted the low offer and they became the new owners. "I learned that you have to watch out about what you make an offer on," he said.

The couple intended to make the silo a second home but that idea fizzled out after awhile and the couple prepared to put the property up for sale. "Before we sold it, I wanted to dive in the silo to see what was in the water," Hannifin said. He said he and a group of fellow instructors dived in and came up saying, "Hey, that's pretty neat!"

During the third dive outing at the silo, a few advanced student divers earned deep-diving certifications so the idea of marketing dive-training trips in addition to recreational "fun" dives gave the Hannifins the idea of converting the silo from a residential property to a commercial one. A series of water and radiation tests proved the silo was safe, so the couple began improving the site for more dive trips.

A recent class session at the silo had Hannifin with four students, one doing a nitrox dive while the other three worked out scenarios for a rescue class. The rescue students would have to form a plan for an emergency and list some of the problems divers might face in a missile-silo environment. While portions of the surface skills could be conducted in the silo, Hannifin said the rest of the rescue class' dives would be held in a shallower lake area. "A missing diver would be too easy to find here, so we'll do that at a lake," he said.

Divers can follow a down line from a buoy to the bottom of the structure where steel debris crisscrosses the area. "We recommend you don't go below 110 feet," Hannifin said. After inspecting the bottom, a return trip up the silo's curved wall reveals evidence where groundwater has seeped into the structure by the formation of thin calcium deposits that look like clumps of string. Around 60 feet (18 m) a ladder extends up to the only structure remaining in the silo's shaft — an inertial guidance system shack that you can barely squeeze into without kicking up too much silt. Beyond the shack are a series of large steel bumpers scaling up the wall. They offer divers reference points and something to inspect while conducting safety stops before reaching the surface.

While hauling your dive gear and tanks down to the staging area and water's surface is challenging enough, the trip back up the series of stairs with the equipment makes you wish that Hannifin's next improvement to the structure would be an elevator. But that's a small price to pay to write in your logbook that you dived in the "hall of fallen heroes," something an 82-foot- (25-m-) long nuclear missile used to call "home."

Contact Information

Dive Valhalla is only accessed through reservations made through Family Scuba Center in Midland, Texas, at (866) 217-2822, (432) 686-7333 or at If not part of a scheduled class, recreational divers are charged a usage fee with a minimum number of divers in a group needed to secure the reservation. To reach the unmarked locked gate of the silo's property, take Interstate 20 to Abilene and then U.S. Highway 277 south. Lodging and restaurants are plentiful in Abilene and you can find a listing of them through the city's chamber of commerce at (915) 677-7241.