A photo of the Coast Guard enforcing Prohibition. [The CG-100, one of the 203 75-foot patrol boats built specifically for Prohibition enforcement duties. They were known as the "Six-Bitters" and entered service between 1924 and 1925. They had a top speed of 15 knots, slower than most of the rum-runners they were up against but were known as sturdy, well-built craft capable of off-shore operations.]A photo of the Coast Guard enforcing Prohibition.