"The submarine presents a problem such as the world at large has never dreamed of before. The Kaiser's deep sea monsters represent the most perfect engines of Hell that the evil genius of man has been able to devise," writes Ens. George S. Dole of submarine chaser SC 93, on 7 July, 1918. The chasers were on the barrage line, learning on the job how to detect and pursue enemy subs.

The technology was new, the boats were new, and the crews were green. "There are many tough problems to be solved, but they will be solved quickly," Dole remarks. For the remaining months of the war, U.S submarine chasers would serve on the barrage lines, learning the science of antisubmarine warfare and working to prevent U-boats from gaining access to open ocean.

Photo: Subchaser SC 95 and other chasers on the barrage line. From Hunters of the Steel Sharks: The Submarine Chasers of WWI.