German U Boats Had 45 Seconds To Crash Dive Before Allied Bombers Attacked Discover how ⚓️ the fate of the Atlantic turned in a matter of seconds during World War II, when the once-invincible German U-boats became the hunted instead of the hunters. In early 1943, British and American forces unleashed groundbreaking radar technologies that ended the submarines’ vital 45-second window to crash dive and evade attack. From the invention of centimetric ASV Mark III radar and the blinding Leigh Light