The real lesson of the Falklands submarine war Bigger isn’t better underwater

In its detailed examination of undersea combat during the Falklands War, War on the Rocks revisits one of the rare post–World War II naval conflicts where submarines played a decisive operational role. Far from a nostalgic case study, the article reads as a pointed warning to today’s naval planners: in shallow, cluttered littoral waters, size, firepower, and even experience matter far less than stealth, manoeuvrability, and an intimate understanding of the environment.

The central argument is clear and compelling. The Falklands campaign demonstrated that undersea warfare in coastal waters is governed by radically different dynamics than the open-ocean battles that still dominate much naval thinking. In the noisy, irregular seabeds around the islands — filled with wrecks, kelp, and geological clutter — sonar performance degraded dramatically. Detection became uncertain, contacts ambiguous, and anti-submarine warfare (ASW) hunts chaotic. British forces, despite their technical and operational superiority, repeatedly attacked whales, seabed features, and even flocks of seabirds while chasing the elusive Argentine submarine ARA San Luis.

The San Luis episode is the article’s most striking illustration of asymmetric impact. Despite mechanical failures, an inexperienced crew, and zero confirmed kills, the small diesel-electric submarine imposed a disproportionate strategic cost on the Royal Navy. Its mere presence forced British commanders to slow operations, divert scarce ASW assets, and accept uncertainty across the battlespace. This “threat-in-being” effect highlights a crucial insight: in littoral warfare, denying the enemy confidence can be as powerful as destroying their ships.

By contrast, the fate of ARA Santa Fe underscores the penalties of size in shallow waters. Too large to dive safely in 40–50 metres of depth, the ageing submarine was trapped near the surface and rapidly neutralised by British helicopters. The article makes a crucial point here: this was not primarily a failure of technology or age, but of physics. A large hull with deep draft and limited vertical clearance simply cannot survive sustained operations close to shore.

The sinking of ARA General Belgrano by HMS Conqueror completes the triad of lessons. One successful torpedo attack eliminated Argentina’s surface fleet as a factor in the war, granting Britain freedom of manoeuvre at sea. Undersea dominance reshaped the entire campaign, shifting the fight decisively into the air domain. The message is blunt: control below the surface often determines outcomes above it.

From these episodes, War on the Rocks draws broader implications for future force design. In contested littorals — from the Baltic to the South China Sea — large submarines optimised for endurance and payload may find themselves constrained, noisy, and vulnerable. Smaller, quieter platforms with modest but realistic weapon loads are better suited to exploit brief firing windows and survive the inevitable counterattack. The article also highlights the growing role of unmanned underwater vehicles as force multipliers, pushing sensing and attrition away from high-value manned submarines.

Ultimately, the analysis challenges long-standing assumptions about submarine power. Bigger is not always better. In shallow, noisy waters, stealth achieved through compact design, disciplined operations, and environmental exploitation outweighs sheer displacement or magazine size. Four decades after 1982, the Falklands War remains less a historical curiosity than a blueprint — and a warning — for how undersea warfare will be fought in the world’s most likely future maritime flashpoints.

By Vugar Khalilov