In this day before sonar, a submarine traveled utterly blind, trusting entirely in the accuracy of sea charts. One great fear of all U-boat men was that a half-sunk derelict or an uncharted rock might lie in their path.
Erik Larson
In this day before sonar, a submarine traveled utterly blind, trusting entirely in the accuracy of sea charts. One great fear of all U-boat men was that a half-sunk derelict or an uncharted rock might lie in their path.