Meet 7 of the fastest submarines ever to dive beneath the ocean waves

For more than a century, submarines have quietly evolved from slow underwater boats into some of the fastest and most sophisticated machines ever engineered. While stealth remains the defining characteristic of modern submarines, speed can still make the difference between intercepting an adversary, escaping danger, or reaching a strategic position first. Interestingly, many of the fastest submarines ever built emerged during the Cold War, when the Soviet Union and the United States competed to push underwater engineering to its limits. Some designs prioritized sheer speed at the expense of noise and operating costs, while modern submarines increasingly balance speed with stealth. Here are seven of the fastest submarines ever built. 1. Project 661 Anchar (Papa class) – 44.7 knots (82.8 km/h) The Project 661 Anchar, better known by its NATO reporting name Papa class, remains the fastest submarine ever built. Developed by the Soviet Union during the Cold War, the titanium-hulled nuclear-powered cruise missile submarine reportedly reached an astonishing 44.7 knots during sea trials. A record that still stands today. Its extraordinary speed was made possible by two powerful nuclear reactors and an advanced titanium hull that reduced weight while allowing deeper dives. However, these achievements came at a cost. The submarine was extremely expensive to build, mechanically complex, and notoriously noisy at high speeds, making it easier for enemy sonar to detect. Only one vessel, K-162 (later K-222), was ever constructed, but it remains one of the greatest engineering achievements in submarine history. 2. Project 705 Lira (Alfa class) – 41 knots (76 km/h) If one submarine embodied Soviet engineering ambition, it was the Alfa class. Introduced in the 1970s, it combined a lightweight titanium pressure hull with a revolutionary liquid-metal-cooled nuclear reactor, allowing it to accelerate faster than almost any other submarine of its era. With a reported top speed of around 41 knots, the Alfa could outrun many torpedoes of the time and rapidly change depth, making it exceptionally difficult to engage. However, its advanced reactor proved difficult and expensive to maintain, ultimately limiting widespread deployment. Even so, the Alfa remains one of the most technologically ambitious submarines ever placed into service. 3. Seawolf class – More than 35 knots (65 km/h) Unlike many earlier fast submarines, the U.S. Navy’s Seawolf-class attack submarines were designed to combine high speed with exceptional stealth. Although the Navy has never officially disclosed the class’s maximum speed, publicly available estimates place it at over 35 knots while submerged. Built to counter advanced Soviet submarines during the closing years of the Cold War, the Seawolf features a powerful nuclear propulsion system, advanced sonar, and extensive acoustic quieting measures. Only three Seawolf-class submarines were built because of their enormous cost, but they remain among the most capable attack submarines in the world. 4. Project 885 Yasen class – About 35 knots (65 km/h) Russia’s Yasen-class nuclear-powered attack submarines represent the country’s most advanced multi-role submarine design currently in service. With publicly reported submerged speeds of approximately 35 knots, the Yasen combines impressive performance with modern stealth features and a formidable weapons suite capable of launching Kalibr, Oniks, and Zircon cruise missiles. Rather than focusing solely on speed, the design emphasizes survivability, long-range strike capability, and reduced acoustic signatures, reflecting the priorities of modern submarine warfare. 5. Project 971 Akula class – About 35 knots (65 km/h) The Akula class marked a significant leap forward in Soviet submarine design by combining high underwater speed with dramatically improved quieting. Capable of roughly 35 knots while submerged, the Akula was considerably quieter than many earlier Soviet submarines, making it a more formidable adversary for NATO forces. Its combination of speed, endurance, deep-diving capability, and powerful torpedo armament has allowed several upgraded variants to remain in service decades after they first entered operation. 6. Sierra class (Project 945) – About 34 knots (63 km/h) Like the Alfa and Papa classes before it, the Sierra class employed a titanium pressure hull, enabling greater diving depths while reducing weight. With an estimated submerged speed of around 34 knots, the Sierra was designed for high-speed interception and deep-water operations. Titanium construction also provided excellent corrosion resistance and survivability, although the material’s high cost meant relatively few boats were produced. Many of the engineering lessons learned from titanium-hulled submarines later influenced subsequent Russian submarine designs. 7. Virginia class – More than 34 knots (63 km/h) The Virginia-class attack submarine demonstrates how modern submarine design has evolved beyond the pursuit of outright speed. Public estimates place its maximum submerged speed at more than 34 knots, although the U.S. Navy has never officially confirmed the figure. Instead of chasing speed records, the Virginia class emphasizes stealth, advanced sensors, modular payloads, and multi-mission flexibility, allowing it to conduct intelligence gathering, anti-submarine warfare, land-attack missions, and special operations support. Today, it is widely regarded as one of the world’s most capable and versatile nuclear-powered attack submarines. Speed isn’t everything underwater Although these submarines represent some of the fastest ever constructed, modern naval warfare has shown that speed alone does not guarantee superiority. High-speed operation generates additional noise, making submarines easier to detect with sonar. As a result, today’s designers often prioritize stealth, sensor performance, endurance, and weapons integration over setting new speed records.The Cold War produced extraordinary engineering feats like the Papa and Alfa classes, but modern submarines such as the Virginia, Seawolf, and Yasen demonstrate that in underwater warfare, remaining undetected is often more valuable than being the fastest vessel beneath the waves.Recommended ArticlesKaif Shaikh is a journalist and writer passionate about turning complex information into clear, impactful stories. His writing covers technology, sustainability, geopolitics, and occasionally fiction. A graduate in Journalism and Mass Communication, his work has appeared in the Times of India and beyond. After a near-fatal experience, Kaif began seeing both stories and silences differently. Outside work, he juggles far too many projects and passions, but always makes time to read, reflect, and hold onto the thread of wonder.