During World War I, German U-boats took a heavy toll on merchant and military ships. Destroyers were adapted to handle the threat, but enough could not be produced quickly with limited supplies. The ultimate answer was 110-foot Sub Chasers with wooden hulls. The vessels were redefined and redesigned to handle new adversaries during World War II. This book takes a detailed look at US Sub Chasers with more than 100 photographs, color profiles and detailed line drawings. 52 pages.