The Day a Single Submarine Sunk Two Battleships Without Any Backup or Reinforcements

On November 21st, 1944, in the narrow waters of the Formosa Strait, a single American submarine accomplished what naval doctrine said could not be done.

USS Sealion II, operating alone and without any backup, encountered two Japanese battleships—Kongo and Haruna—veterans of the Imperial Japanese Navy, heavily armored, fast, and protected by destroyer escorts. Battleships were not supposed to be submarine targets. They were too large, too well-defended, and too dangerous to engage directly.

Commander Eli Reich disagreed.

Rather than attacking from the edges of the formation, Reich identified a critical structural weakness most commanders overlooked: a battleship’s keel. Designed to support massive weight rather than absorb explosions, it was vulnerable to torpedoes striking from below. Exploiting this flaw required extreme precision, perfect timing, and positioning directly beneath moving capital ships—a maneuver that left no margin for error and no escape if detected.

As destroyers searched outward for a conventional attack, Sealion II maneuvered inside the escort screen, lying in wait beneath the battleships’ path. What followed was one of the most audacious submarine attacks of World War II. In less than an hour, both Kongo and Haruna were mortally damaged, their hulls structurally broken, and eventually lost to the sea.

This video explores how a single submarine commander challenged every assumption of naval warfare, how Japanese escort doctrine failed to anticipate an attack from below, and why this engagement forced a quiet reassessment of battleship survivability in the final year of the war.

This is not a story of brute force or overwhelming firepower. It is a story of preparation, geometry, psychology, and the willingness to act where doctrine said survival was impossible.

DISCLAIMER

This video is intended for educational, historical, and documentary analysis purposes only.

The events discussed are based on documented World War II naval operations, declassified patrol reports, and established historical research. To improve clarity and narrative flow, certain descriptions, pacing, and scene reconstructions may be dramatized while remaining consistent with the historical record.

This content does not glorify war, violence, or military conflict. It examines naval strategy, decision-making under extreme pressure, and the historical realities of submarine warfare within their wartime context. No political ideology, military action, or act of violence is endorsed.

Any visual reconstructions or AI-generated imagery are used strictly to illustrate historical concepts and should not be interpreted as exact representations of real-world events.

The focus of this documentary is understanding history—not promoting conflict.