The Navy Dive Team

Making the Impossible Look Easy

By CHRISTOPHER C. MURRAY and MICHAEL P. LEESE

Capt. Christopher C. Murray, USN, is the Navy's supervisor of diving at the Naval Sea Systems Command (NAVSEA). Michael P. Leese is a diving project engineer at NAVSEA.

The term "Navy diver" conjures up different images for different people. To some, the phrase suggests a Navy SEAL, his weapon drawn, emerging from the murky depths, with stealth and lethality. Others might imagine a crusty, woolen-capped hard-hat diver fighting at bone-crushing depth to save the lives of Sailors trapped in a disabled submarine.

In truth, the "average" diver is anything but typical. The rare breed of men and women in today's Navy Dive Team play a vital role in a broad spectrum of missions ranging from explosive ordnance disposal to in-water ship maintenance and repair.

The Navy Dive Team actually consists of several different communities within the Navy. The Explosive Ordnance Disposal (EOD) community identifies and disarms explosives underwater. Underwater Construction Teams build and repair piers and underwater support facilities. The submarine rescue mission requires divers qualified in various skills to maintain and operate highly complex equipment both in and out of the water. This article will focus on the "fleet diving" community, also known most commonly as salvage divers and underwater ships-husbandry divers.

There are approximately 1,000 divers in the fleet diving community. Apart from underwater construction divers, fleet divers are the only ones to use surface-supplied diving systems that provide air to the diver through a hose reaching back to the diving platform on the surface. Regardless of their assignment, fleet divers have earned a well-deserved reputation for possessing an intimate knowledge of diving equipment, techniques, and procedures. In wartime, the fleet diver mission entails combat salvage, including battle-damage assessment, stabilization and towing, port restoration, and ships husbandry. Today, most Navy divers serve either on salvage ships (designated ARS or T-ATF), crafts of opportunity (Mobile Diving and Salvage Units), tenders, or in various "dive lockers" throughout the world.

Combat Salvage

An excellent example of fleet divers rendering assistance to a stranded vessel involved the tank landing ship USS LaMoure County in September 2000. A team of Navy divers from Mobile Diving and Salvage Unit Two (MDSU-2) in Little Creek, Va., joined forces with Naval Sea Systems Command (NAVSEA) diving and oil pollution-control contractors to complete one of the largest peacetime ship salvage operations in U.S. naval history.

The LaMoure County, participating in an annual UNITAS exercise, was conducting a routine amphibious landing that involved launching eight amphibious assault vehicles, loaded with 240 Marines and their equipment, ashore on a remote Chilean beach. The LaMoure County was making a predawn approach to the beach when the 522-foot ship ground to a halt. Major flooding soon left the bow trimmed six feet deeper than normal--due, in large part, to a hole in the hull approximately 40 feet in diameter. Ultimately, the salvage plan focused on three main tasks: oil-pollution control and prevention, structural repairs, and buoyancy restoration.

During the next several weeks, U.S. and Chilean Navy divers and NAVSEA-contracted divers were able to right, stabilize, and strengthen the ship; control the environmental effects of waterborne fuel pollutants; and offload valuable equipment. Underwater welding, the fabrication of massive structural stiffeners, and patching the countless holes in tanks and shell plating fell to the divers.

Navy divers were on the scene for six weeks and installed 22 steel-reinforced patches, plugged more than 50 holes, poured 27 tons of steel-reinforced concrete, and restored 700 tons of buoyancy to the crippled ship. Through a tremendous cooperative effort, Navy divers, engineers, and support contractors kept the LaMoure County afloat and delivered her safely to port.

A Devastating Blast

In another operation with international ramifications, divers responded to the terrorist attack on the guided-missile destroyer USS Cole in Yemen on 12 October 2000. While the Cole was refueling in the port of Aden, terrorists detonated a small boat packed with explosives along the port side of the ship, killing 17 Sailors, wounding 39, and ripping a 1,600-square-foot hole in the hull. EOD divers in the area were the first to respond. After completing a hull search for additional explosive devices, they conducted an initial damage survey that allowed Navy salvage engineers to complete stability calculations.

A detachment of divers from MDSU-2, deployed aboard the fleet ocean tug USNS Mohawk--then at sea near Bari, Italy--also responded to the scene. Their tasks were to locate the missing Sailors, assist with stabilizing the ship, recover evidence, and perform structural inspections. Close to 100 investigators, diving and salvage experts, engineers, and support teams formed the Crisis Response Team the Navy had assembled for the grim task.

The Cole's crew performed at a superhuman level under dangerous and arduous conditions in the days following the attack, but by 15 October it was apparent they would be unable to stop the flooding into Main Engine Room Two, the ship's only remaining engine room still operational. Air temperatures of 100 to 110 degrees Fahrenheit kept water temperatures around 90 F, creating dangerously dehydrating conditions for the backbreaking work.

The blast area on the ship was nothing less than devastating. Port and forward bulkheads were blown inward, all nonwatertight doors had broken from their hinges, filing cabinets lay scattered across the deck, and visibility was reduced to less than three inches. Through the continued efforts of the Navy divers on site, the ship was stabilized, and all of the missing Cole Sailors were recovered--they were given full military honors as they were escorted off the ship to begin their long and final journey home.

With the recovery phase completed, the dive team began the inspection dives needed to assist naval engineers in determining how much of the Cole's structural strength had been lost. The Blue Marlin, a 700-foot-long Norwegian heavy-lift transport ship, was contracted to return the Cole back to the United States. To accommodate the Cole, the Blue Marlin was fitted with special docking blocks. Two large guideposts maintained the destroyer in the proper position over the blocks. The keel blocks were shortened to provide extra stability and two large holes were cut into the transport's deck to allow the Cole's propellers to extend downward. The Cole was positioned 19 degrees off center on the deck so her sonar dome could hang over the side of the Blue Marlin's deck.

The fleet ocean tug USNS Catawba towed the Cole out of Aden's harbor on 29 October to deeper waters approximately 23 miles off the coast of Yemen. Loading the Cole onto the Blue Marlin required calm seas and a water depth of at least 75 feet. The Blue Marlin partially submerged as tugs maneuvered the Cole into position over the transport's deck. Three scuba dive teams guided the damaged destroyer into position as the Blue Marlin raised up in the water to meet the ship. The forward dive team reported on the sonar dome's position and forward keel block, while two aft dive teams reported on the propellers as they entered the cutouts, the aft keel block, and the port and starboard side blocks. The entire docking evolution took almost 24 hours to complete. The Blue Marlin, with the Cole securely held on her deck, began the transit back to the United States.

The Underwater World Of Ships Husbandry

Providing the means for Underwater Ships Husbandry (UWSH) is another crucial capability that fleet divers deliver to the Navy. UWSH divers save the Navy--and U.S. taxpayers--millions of dollars annually completing ship repairs in the water. The alternative would be to place the ship in drydock--a much more expensive and time-consuming option. In addition to the cost savings, UWSH offers operational advantages by allowing a ship to be returned to service without the need for a tow to the site of an expensive dry docking where the ship may have to wait in line.

UWSH divers usually spend more of their time working underwater than do their counterparts assigned to sea duty as they complete the repairs needed to allow ships to get underway to meet tight deployment commitments. The skills they develop in becoming experienced experts also are helpful in preparing them for wartime missions. A seasoned UWSH diver is a valuable asset in carrying out combat salvage missions.

Navy divers completed extraordinary ship-husbandry feats underwater when they replaced two propellers on the nuclear-powered aircraft carrier USS John C. Stennis in August 1999. Divers from Consolidated Divers Unit (CDU) San Diego, Calif., and Puget Sound Naval Shipyard (PSNS) Wash., safely coordinated the removal and replacement of the 63,000-pound propellers at Naval Air Station North Island, Calif.

A combined crew of 16 Navy divers, six civilian shipyard divers, and a NAVSEA diver/engineer worked side by side both on the surface and in the water--12 hours a day for 20 days. Two dive stations, loaded with tools and other equipment items that were neither lightweight nor very portable, were used periodically to support up to five surface-supplied divers in the water at one time

A crane transferred rigging, lifting fixtures, and tools to the water's edge, while a combination of lift bags, chain falls, a pneumatic winch, and--probably the most important tool of all--diver ingenuity enabled everything to be moved to and from the work site. Three 50-ton hydraulic chain falls were used to yard and stay the propellers from their shafts to strongbacks attached to a floodable counter-ballast tank on a barge. Once transferred to the strongback, the entire barge was moved out from under the carrier flight deck's overhang, the propeller was transferred to the pier crane, and the new propeller was lowered and rigged in the water for the divers to install.

Navy divers carried out another unusual ships-husbandry assignment with the in-water replacement of the rudder pin on the aircraft carrier USS Constellation. Ten days before the Constellation was due to depart for a planned deployment, NAVSEA's supervisor of diving and salvage learned that the carrier could not deploy because its starboard rudder pin had somehow been damaged, creating a serious risk that the rudder could fall off.

NAVSEA immediately dispatched a diving officer to San Diego to lead the field operation, while a dive team from Puget Sound Naval Shipyard, the Consolidated Diving Unit, and NAVSEA's commercial diving contractor was assembled. Within 24 hours of the call, the dive team developed a workable plan to repair or replace the rudder pin, set up the equipment for the job, and went into the water to begin repairs. The team started by welding four 25-ton pad-eyes to the hull and attaching four heavy hydraulic lifts to raise the damaged 50,000-ton rudder.

After a two-and-a-half-day around-the-clock effort to extract the pin's damaged key from the rudderstock the rudder was lifted and its damaged pin was removed. As a cautionary measure, the team decided to repair and "dewater" the flooded port rudder as well. Under NAVSEA's leadership, one team installed the new key, while the other conducted underwater welding operations on the port rudder, sealing it from the sea and dewatering it with nitrogen. Finally, with the new key installed and shimmed, underwater welders closed up the starboard rudder, and the ship was able to get underway. As a result of the team's hard work, the Constellation deployed only one week behind schedule.

Even during peacetime, fleet divers stay busy. Aside from the never-ending task of underwater ships husbandry to keep Navy ships afloat and out of dry dock, the varied work of diving-and-salvage commands continually provides immeasurable peacetime dividends. Navy divers have conducted a myriad of historic salvage-and-recovery operations, including those associated with the space shuttle Challenger, TWA Flight 800, the Japanese fishing vessel Ehime Maru, and the wreckage of John F. Kennedy Jr.'s private aircraft. Responding to some of the greatest U.S. and international tragedies at sea is a recurring mission. When the recovery of bodies also is required, it is an especially challenging and solemn task of immense importance to family members. When disaster strikes and the eyes of the world focus on the televised images of the rolling sea, Navy salvors respond with uncompromising confidence.

Raised From the Deep

Salvage-and-recovery operations are not always fraught with the overwhelming sadness associated with disasters at sea. Navy divers also have the privilege--and pleasure--of supporting important scientific and archeological projects. One of the most publicized operations of this nature involves the ongoing efforts to raise historical artifacts from the wreck site of the illustrious ironclad USS Monitor.

The famed Civil War craft--best known for its battle with the Confederate ironclad CSS Virginia (the USS Merrimac until her capture by Confederate forces) in Hampton Roads, Va., in 1862--sank during a vicious storm off the coast of North Carolina a few months later. In 1997, the NOAA (National Oceanographic and Atmospheric Administration) preservation team responsible for the wreck site determined that the Monitor's historical gravesite was deteriorating at an alarming rate and that the ship's main structural components had to be brought to the surface quickly or be lost forever. That is when Navy divers came to the rescue.

For the past five years, the Navy has teamed with NOAA and The Mariners' Museum by conducting annual expeditions to the site. At a depth of approximately 240 feet, the conditions for archeological scrutiny are daunting at best. But, with the help of underwater video systems and thousands of hours of time on the bottom, the rescue team's achievements have exceeded expectations each summer. Navy divers have thus far recovered the vessel's propeller, portions of its shaft, and the ship's skeg. The Monitor's sagging hull also has been shored up.

During Monitor Expedition 2001, with the added benefit of the use of a commercially owned Navy-operated saturation diving system, the team safely recovered the vessel's aging steam engine--a technical wonder of its time.

Saturation diving is the name given to the practice of maintaining divers at bottom depth for many days at a time through the use of an enclosed bell system. With this technique, decompression is required only once instead of at the end of each dive. This capability allows dive teams to log many additional hours of bottom time. Saturation diving was part of the Diving Navy's regular bag of tools for many years until the decommissioning of the Navy's last saturation-dive platforms in the 1990s. The Monitor missions have demonstrated a successful "proof of concept" for the Navy's use of commercial fly-away saturation diving systems.

This summer's Monitor Expedition is the most ambitious of all, because the team is using both surface-supplied and saturation-diving systems to recover the Monitor's distinctive gun turret. Included in the list of potential artifacts are the two Dahlgren cannons made famous in the battle with the Virginia. All of the artifacts recovered are destined for conservation and eventual display at The Mariners' Museum in Newport News, Va.

Working steadily, often heroically, through tragedy and triumph, the Navy Dive Team is always available to tackle the most demanding tasks encountered in the watery depths of the maritime domain. Bound by the requirement not only to breathe but also to work effectively underwater, Navy divers are adding new chapters to their rich historical legacy. There is no way to predict what mission may come their way next, but the certainty is that Navy divers will be ready for the challenge. *