What new technology did German U-Boats use late in the war to address Allied antisubmarine defenses?

During World War II, German U-Boats faced increasingly sophisticated Allied antisubmarine measures, making it necessary for them to adapt their strategies and technologies to survive and remain effective. The introduction of snorkels was a significant technological advancement that allowed U-Boats to operate more effectively while submerged.

Snorkels permitted the submarines to draw in air from above the surface while remaining submerged, allowing them to run their diesel engines without having to surface frequently, which significantly reduced their vulnerability to aerial and surface attacks. This capability enabled them to operate for longer durations underwater, thus providing a tactical advantage against Allied ships and aircraft that were actively hunting for submarines.

In contrast, while nuclear propulsion, sonar jamming systems, and advanced torpedoes represent significant advancements in naval warfare, these particular technologies were not employed or developed by German U-Boats during World War II to counteract antisubmarine defenses at the late stage of the war. The snorkel was notably pivotal in enhancing the survivability and operational effectiveness of U-Boats against Allied threats.