Navy Stealth Ship to Disappear — Permanently
Byline: Jack Innis
A mysterious and odd-shaped Navy stealth ship formerly homeported in San Francisco and San Diego is disappearing permanently after being sold at auction this month.
Although the 164-foot catamaran Sea Shadow plied California waters for more than 30 years, relatively few boaters ever saw the secret ship by day and, it is safe to say, none saw it on radar at night.
One of the more radical ships ever floated, Sea Shadow was built in 1985 at the end of the Cold War under a shroud of secrecy in the backwaters of South San Francisco Bay near Redwood City. The $50 million test bed for maritime stealth technology was constructed by Lockheed Martin inside a covered barge, to avoid the prying eyes of foreign spy satellites. The 27-month build was so hush-hush that subcontractors who created each of the craft’s four modular subsections offsite had no inkling what the ship would look like after the modules were welded together.
“The vessel was built in modules and trucked or barged in under cover of night,” said Steve Larson, former designer. “None of these other fabricators at the other locations had any idea of what we were doing, and sometimes we were simply known as ‘Acme Engineering’ to them. The roof of the barge was opened at night and a floating crane would lower each module into it. The roof would not be opened if any Russian satellites were known to be overhead.”
From the time it was launched, Sea Shadow excelled as a test bed for radar-avoiding technologies. The 68-foot-wide vessel might best be described as an A-framed catamaran floating on a pair of underwater pontoons that extended 14.5 feet underwater. The vessel’s solid side walls, which tilt toward one another at the peak to scatter radar beams, were covered with highly classified radar-absorbing materials. Sea Shadow’s flat-black surface paint made it nearly impossible to spot at night visually, even with powerful binoculars.
Sea Shadow was so stealthy that it once crept up on an aircraft carrier during a nighttime naval exercise. The stealth vessel remained completely unnoticed until it fired three flares. Even after the flares were fired, lookouts couldn’t locate Sea Shadow and it didn’t show up on radar until the crew opened one of its flush-fit deck hatches.
Although Sea Shadow’s radical A-frame hull never caught on for active duty fleet, other features of the vessel’s construction can be seen in modern warship design. The Navy’s new fleet of littoral combat ships (LCS) is constructed to minimize flat areas on hulls and superstructures that tend to reflect radar signals. Nuances of stealth architecture can be seen in contemporary Navy ships such as the Arleigh Burke-class guided missile destroyers. And as current fleets of destroyers, frigates, cruisers and aircraft carriers age, their replacements will no doubt feature stealth technologies derived from Sea Shadow.
Few Creature Comforts
Most vessels, from kayaks to cruise liners, are built on compromises and tradeoffs. Sea Shadow was no exception. Sloping hulls built to scatter radar signals didn’t allow much interior space and most interior voids were so packed with basic propulsion and navigation equipment that, unofficially, the vessel had room no for any sort of weapons system. Crew space was limited too.
“Berthing is Navy standard for the era with 12 berths provided,” according to the Historic Naval Ships Association (HNSA). “A typical (ship’s complement) consisted of eight standing crew operating the ship and four working the payload. However, on some missions as many as 24 were aboard and some slept on cots in the payload space.”
Despite twin 800 hp diesel electric engines that gave Sea Shadow a range of 1,000 nautical miles at 10 knots, the 560-ton vessel was designed for short-duration missions, typically three to five days. With onboard space at a premium, the crew had to make due with one toilet and shower. The ship’s galley was limited to a sink, a food locker, a domestic-size refrigerator, a 12-cup coffeemaker and a microwave oven. Food, often a singular point of solace in a weary sailor’s day, was served on a metal picnic table. The chow hall fare was so basic that one former crewman commented, “We survived the food, but that was it.”
But, in another tradeoff, Sea Shadow was known to ride very well in heavy seas. In fact, stories have surfaced that Navy or Coast Guard escort ships at times had to abandon their chaperone duties due to high seas while the stealth ship continued on course, but it’s hard to determine the veracity of these tales.
Regardless of whether escorts ever turned tail due to rough conditions, Sea Shadow took advantage of an advanced computer-controlled underwater stabilizing system to smooth out the ride. Lacking conventional rudders, Sea Shadow was steered and steadied by stabilizing fins located on the after portion of each underwater pontoon. Canards, or forward stabilizers located near the tips of the pontoons, provided additional stability.
Under the mantle of darkness, night tests were conducted off Santa Cruz Island in 1985 and 1986. To shield the experimental vessel from spy views, Sea Shadow rode to the testing grounds aboard the barge upon which it was built and stored. When all was ready, the 324-foot-long barge’s hulls partially submerged, a 76-foot-wide by 72-foot-tall door opened and Sea Shadow motored out.
For reasons never made public, the Navy sidelined Sea Shadow in 1986. In 1993, the vessel was reactivated and spent several months undergoing hull stress tests in various sea states throughout the Channel Islands and off Point Conception.
After the 1993 tests, the Navy went public with Sea Shadow and openly operated it on San Francisco Bay. Shortly thereafter, the stealth ship was deactivated and towed inside its barge to San Diego, where it berthed at the 32nd Street pier.
The vessel was reactivated in 1999 and, in full view of surprised boaters, began transiting San Diego Harbor on a regular basis. The Sea Shadow project was cancelled in 2006.
The total cost of the stealth ship project was $195 million.
The vessel and barge were towed to San Francisco Bay and moored temporarily at Alameda Naval Air Station, according to published reports. On at least one occasion, Sea Shadow stunned Bay Area boaters by gliding under the Golden Gate Bridge, making a day trip to sea. Boneyard Fleet
The Navy soon moved the stealth ship to the Maritime Administration National Defense Reserve Fleet in Suisun Bay, a rather lofty term for boneyard, and struck Sea Shadow from its duty roster. (Historians will note that Sea Shadow never received the USS designation of an active duty Navy vessel).
But the Navy did not want Sea Shadow to spend the rest of its days moored with Suisun Bay’s rust bucket fleet. Hoping to preserve this piece of Cold War history, officials placed a “donation hold” on Sea Shadow and quietly worked to find a museum to host the stealth ship and barge.
Finding no takers, the Navy eventually advertised the giveaway in the Federal Register. The only interested party turned out to be the USS Ranger Foundation in Portland, Oregon. But the group, which is still negotiating to obtain the aircraft carrier, actually wanted Sea Shadow as barter for yard work for its aircraft carrier, according to published reports. That deal fell through and no other qualified suitor could be found.
Sources familiar with maritime museum operations point out that the stealth ship’s lack of traditional deck space and cramped interior makes conducting tours exceedingly difficult. Without tours turning turnstiles and generating cash flow, the stealth ship would likely languish in a sea of red ink.
Unwilling to pay to keep the ship afloat, the Navy recently decided to sell Sea Shadow through a Government Services Agency internet auction. Would-be buyers with dreams of converting the stealth ship into a boat and breakfast inn, or simply having the world’s coolest toy (the Darth Vader-like hull served as inspiration for the villain’s vessel in the 1997 James Bond movie “Tomorrow Never Dies”) had their collective hopes dashed when they read the auction’s fine print: Sea Shadow must be completely dismantled.
“Dismantling is defined as reducing the property such as it has no value except for its basic material content,” auction terms state.
The winning bidder gets to keep Sea Shadow’s barge, which does not need to be dismantled. The barge has a secret history of its own.
Hughes Mining Barge (HMB-1) was built for the Central Intelligence Agency in 1973 by Howard Hughes to salvage Soviet submarine K-129 after it sank in 16,000 feet of water northwest of the Hawaiian island of Oahu in 1968. HMB-1 allegedly worked with Glomar Explorer to house a large claw that grappled the submarine and, after raising the stricken craft, concealed the recovered submarine.
Sea Shadow sits on death row, so to speak, its future certain. Sold at auction for $3.2 million, the ship will be stripped of useable parts before succumbing to dismantlers’ oxyacetylene torches. No doubt chunks of steel that once formed the former stealth vessel’s hull and superstructure will someday be unceremoniously dropped into a rail car and freighted to a foundry for repurposing: cars, high-rise offices, razor blades?
To help preserve Sea Shadow’s memory, HNSA commissioned San Pedro photographer Bruce Ecker to capture images of the historic ship and barge. The Navy graciously granted Ecker five days aboard Sea Shadow in the summer of 2011. HNSA laced Ecker’s photos together to create a virtual tour with a drag and click feature that allows 360 degree viewing from various points aboard the ship and barge.
After spending its life avoiding detection, Sea Shadow will soon disappear permanently. Vestiges of the stealth ship may be viewed at hnsa.org.