On 27 April 1943, Commander Fluckey assumed command of Barb (SS-220).

As commanding officer of Barb, he established himself as one of the greatest submarine skippers, credited with the most tonnage sunk by a U.S. skipper during World War II: 17 ships including a carrier, cruiser, and frigate. In one of the stranger incidents in the war, Fluckey sent a landing party ashore to set demolition charges on a coastal railway line, which destroyed a 16-car train. This was the sole landing by U.S. military forces on the Japanese home islands during World War II. . . .

During his famous eleventh patrol, he continued to revolutionize submarine warfare, inventing the night convoy attack from astern by joining the flank escort line. He attacked two convoys at anchor 26 miles inside the 20 fathom (37 m) curve on the China coast, totaling more than 30 ships. With two frigates pursuing, Barb set a then-world speed record for a submarine of 23.5 knots (44 km/h) using 150% overload. For his conspicuous gallantry and intrepidity, Fluckey received the Medal of Honor. Barb received the Presidential Unit Citation for the eighth–eleventh patrols and the Navy Unit Commendation for the twelfth patrol. . . .

Of what was he most proud? "Though the tally shows more shells, bombs, and depth charges fired at Barb, no one received the Purple Heart and Barb came back alive, eager, and ready to fight again."