At the RIMPAC 2000 exercise, the HMAS Waller, a Collins-class submarine, scored simulated kills on US Navy assets. The target set reportedly included an aircraft carrier and various escorts. So how does a conventionally powered submarine penetrate one of the most advanced naval defenses in the world?
What Happened? A Cheap Sub Sinks an Expensive Nuclear Supercarrier
Nimitz-class aircraft carrier USS Abraham Lincoln (CVN 72) departs following a replenishment-at-sea with fleet replenishment oiler USNS Henry J. Kaiser (T-AO-187) during Operation Epic Fury, March 18, 2026. (U.S. Navy photo)
The Waller was tasked with serving as the opposing force (OPFOR) to penetrate a carrier strike group’s defenses.
To execute, the Waller evaded surface ships and ASW aircraft, then achieved a firing position and simulated a torpedo attack. In terms of the war game, the Waller “sank” multiple ships under exercise conditions. The incident demonstrated the vulnerability of even high-end naval formations.
Battery Stealth
The Waller pulled off the upset with diesel-electric propulsion, which is extremely quiet when operating on battery power, giving the Waller a stealth advantage. The exercise also took place in the littorals, which are shallow, complex waters—difficult sonar conditions—which gave the Waller further advantage.
During the exercise, the Waller was patient, with deliberate and slow movements and long-duration tracking, all while maintaining acoustic discipline. Eventually, the Waller got inside the CSG’s defensive perimeter; success was earned through stealth, not speed or firepower.
An F/A-18F Super Hornet, attached to Strike Fighter Squadron (VFA) 41, is taxied on the flight deck of Nimitz-class aircraft carrier USS Abraham Lincoln (CVN 72) in support of Operation Epic Fury, March 6, 2026. Abraham Lincoln is deployed to the U.S. 5th Fleet area of operations to support maritime security and stability in the Middle East. (U.S. Navy photo)
The incident forced the US Navy, the world’s most powerful, to reassess its ASW capabilities. The key lesson was that diesel submarines, though technically outdated, posed a serious threat.
The Collins-class Explained
The HMAS Waller is a Collins-class submarine. Measuring 77.8 meters long, the Collins displaces 3,400 tons when submerged. Using a diesel-electric propulsion system, the Collins operates on battery power when submerged and can achieve 10 knots at the surface or 20 knots submerged.
The submarine’s range is 11,000 nautical miles, well short of the unlimited range that a nuclear submarine offers.
The Collins sails with a crew of 58 personnel and carries six 533mm torpedo tubes capable of launching either torpedoes or anti-ship missiles.
The Collins is also outfitted with an advanced sonar suite offering a passive detection focus. In short, the Collins is designed for long-range, stealthy patrols rather than brute force.
The design philosophy focuses on stealth; the operational concept is for an ambush platform.
This is optimal for the Indo-Pacific, which is defined by long distances. And though the Collins-class has less endurance than nuclear submarines, it is quieter in certain conditions. Essentially, the Collins gives Australia a regionally dominant platform rather than a tool for global power projection.
Persistent Problems
The Collins-class, however, has endured problems. Initially, engine reliability and noise concerns persisted; the combat system showed flaws.
The public perception of the submarine was negative; it was heavily criticized and mocked, and was generally considered a drain on resources.
But incremental upgrades and system refinements have transformed the Collins into a capable platform.
Diesel vs. Nuclear
While nuclear submarines are more prestigious, more expensive, and more heralded, the diesel-electric option does offer advantages.
For example, the diesel power plant is quieter at low speeds and harder to detect.
POLARIS POINT, Guam (May 7, 2013) The Los Angeles-class attack submarine USS Albuquerque (SSN 706) arrives in Apra Harbor, Guam, to conduct maintenance and liberty. Albuquerque is conducting operations in the U.S. 7th Fleet area of responsibility. (U.S. Navy photo by Mass Communication Specialist 1st Class Jeffrey Jay Price/Released)
PACIFIC OCEAN (Dec. 17, 2025) – Los Angeles-class fast-attack submarine USS Annapolis (SSN 760) steams forward off the coast of Guam during a photo exercise, Dec. 17, 2025. Assigned to Commander, Submarine Squadron 15 at Polaris Point, Naval Base Guam, Annapolis is one of five fast-attack submarines forward-deployed in the Pacific. Renowned for their unparalleled speed, endurance, stealth, and mobility, fast-attack submarines serve as the backbone of the Navy’s submarine force, ensuring readiness and agility in safeguarding maritime interests around the world. (U.S. Navy photo by Lt. James Caliva)
Of course, the nuclear option has unlimited endurance and a higher sustained speed, offering a true global platform. But the diesel sub is ideal for ambushes, making the platform optimal for navies with regional ambitions.
Strategic Implications
The RIMPAC 2000 incident demonstrated that carriers are vulnerable; even top-tier defenses can be penetrated.
And diesel-electric submarines represent an asymmetric threat, where cheaper subs pose a legitimate threat to expensive fleets and capital ships.
Many nations operate diesel subs; they are more affordable. So there is a proliferation risk. Despite immense investment in defensive technologies, undersea warfare remains one of the most dangerous domains.
San Diego (Oct. 1, 2005) – The Swedish diesel-powered attack submarine HMS Gotland transits through San Diego Harbor during the ÒSea and Air ParadeÓ held as part of Fleet Week San Diego 2005. Fleet Week San Diego is a three-week tribute to Southern California-area military members and their families. U.S. Navy photo by PhotographerÕs Mate 2nd Class Patricia R. Totemeier (RELEASED)
In today’s strategic environment, the lessons from the Waller remain relevant, especially in the Indo-Pacific, where shallow seas and congested waterways favor quiet, conventional submarines.
For the US Navy, this fact underscores the importance of ASW capabilities, including sonar, unmanned systems, the P-8 Poseidon, and persistent surveillance.
And the Waller incident was hardly an anomaly; other diesel-electric submarines have felled US carriers under exercise conditions, meaning the Waller offered evidence of a broader trend in naval warfare: conventional submarines are dangerous, and vast asymmetries exist in which cheap platforms can do harm to expensive platforms.
About the Author: Harrison Kass
Harrison Kass is a writer and attorney focused on national security, technology, and political culture. His work has appeared in City Journal, The Hill, Quillette, The Spectator, and The Cipher Brief. He holds a JD from the University of Oregon and a master’s in Global & Joint Program Studies from NYU. More at harrisonkass.com.
