Although the US Navy is the uncontested king of the High Seas, a new and ominous threat is growing in the world’s critical coastal waters and maritime choke points – quiet, long-endurance subs, some armed with lethal torpedoes & sea-skimming cruise missiles.

The growing number and increasing sophistication of submarines offer foes a deadly weapon with which to neutralize the United States’ overwhelming combat power and deny its access to critical shipping lanes and seaports.

Such a submarine in the wrong hands could wait undetected for a target – an American aircraft carrier, an amphibious ship packed with Marines, or even a cruise ship jammed with holiday travelers. Result – images on the deadly torpedo wake, a flaming ship upended in the night and the loss of thousands of lives.

Our enemies don’t need to buy a ballistic missile or a huge army, said USN Captain David Yoshihara, head of new Anti-Submarine Warfare task force at the Pentagon in a recent interview. US Navy nuclear attack submarines routinely travel with amphibious ships as scouts and guards. But as the foreign submarine threat grows it could have more strategic impact, vastly complicating the fast and secure movement of warships and logistics support ships on which American military power increasingly depends.

Just as in World War II, indications of a lurking enemy sub would force a naval task force or freighter convoy to take evasive action on a more indirect route or to slow down while US Navy submarines and surface ships swept the seas ahead.

The uncontested undersea superiority experienced during recent conflicts is not likely to be repeated against determined and capable adversaries, Vice Admiral Albert H. Konetzni, Jr. of the Navy’s Fleet Forces Command wrote in a recent essay in Proceedings, the journal of the private US Naval Institute.

More than 400 Submarines in the Oceans

There are already more than 300 foreign submarines in operation, according to estimates by the London based International Institute for Strategic Studies. Some Pentagon officials claim there are more than 400, fielded by 42 nations as diverse as Italy, Singapore, Indonesia, Algeria, Colombia, Croatia and Vietnam. Attack submarines fielded by Pakistan, Egypt, Chile and Turkey, among other countries, carry sea-skimming anti-ship cruise missiles as well as torpedoes.

The submarines themselves run the gamut from rust-bucket to gleaming. The newest use a revolutionary technology enabling them to stay submerged and hidden for weeks. According to Rear Admiral Mark W. Kenny, the Navy’s deputy director for submarine warfare, these boats are very similar to US Navy’s state of the art in capability. Finding them, he said, could be a ‘crap shoot’. The problem had set off alarms within the Navy, which is scrambling to revive sub-hunting skills and technology left formant since Soviet submarines disappeared as a threat more than a decade ago.

Among the new technologies the Navy hopes will help: unmanned or ‘drone’ underwater spy vehicles, continuous active sonar which sends out a streaming ‘PING’ that bounces back to a sensor, air-dropped acoustic sensors that can be ‘seeded’ over a wide area to pick up sound signals, and low frequency sonar that seeks out submarines thousands of miles away and bounces the signal to a nearby killer submarine or destroyer.

All this however, has embroiled the Navy in an ongoing fight with environmentalists who have evidence that sonar harms whales and other marine mammals. While the US Navy operates only nuclear powered submarines with engines that do not require fresh air, most other submarines are powered by diesel engines that need air for combustion. Modern diesel submarines use their engines for fast movement and to charge batteries, but can run silently and slowly on battery power for a few days before having to rise into shallow water to ‘snorkel’ in fresh air.

But the newest submarines use ‘air independent propulsion’ technology….neither nuclear nor diesel….with engines that require no fresh air at all. One new German Type uses a fuel cell to produce electricity from oxygen and hydrogen, which can propel the submarine for weeks of stealthy patrolling.

EDITOR NOTE – Sharkhunters was the first to break the story of the “air independent” submarines some years ago.

Such a submarine could lurk in shallow water, hidden by its silence and the normal clutter of fishing boats and normal maritime traffic. Captain Tom Abernathy commands the ASW Destroyer Squadron 22 in Norfolk, VA said that in shallow water, you get a lot of noise reverberation and additional traffic – and you’re fighting in some one else’s backyard, which they know pretty well. In that environment, a diesel submarine is a real threat, Abernathy said.

The military strategy evolving under the Bush administration makes the problem more acute. Based on the Iraq war model, the Pentagon now envisions a hard strike immediately followed by waves of reinforcements and logistics support ships carrying fuel, ammunition, armored vehicles and troops. This “just in time” support requires fast and dependable schedules with little margin for delay. That means the aircraft, destroyers and submarines that hunt enemy subs must first be able to scan broad areas of water, quickly detect anything lurking – & shoot to kill the very first time.

“We can’t afford to play chess with enemy submarines,” Kenny said. “With the time lines we’re talking about, we have to go right to checkmate.” Yoshihara added that the Navy must be able to quickly sweep large areas to ensure they are free of enemy subs. Strategists worry however, about one lucky submarine to get a hit on a carrier, which has some 5,600 sailors and airmen aboard.