Gilmore commanded his submarine skillfully during four
Pacific War patrols. During his first, on 5 July 1942,
Growler attacked three enemy
destroyers off
Kiska, sinking one and severely damaging the other two, while narrowly avoiding two torpedoes fired in return, for which Gilmore received the
Navy Cross. During his second patrol,
Growler sank four merchant ships totaling 15,000 tons in the
East China Sea near
Formosa for which the Navy awarded him another Navy Cross. During October 1942,
Growler patrolled off Truk in the Caroline Islands as part of a repositioning of submarine assets on the way to Brisbane, Australia. No significant action occurred.
Fourth war patrol and Medal of Honor action , Commandant, Eighth Naval District, bestows the Medal of Honor upon the widow of Howard W. Gilmore.The submarine continued to take a heavy toll on shipping on its fourth war patrol, and during the night of 6–7 February 1943, it approached a
convoy stealthily for a surface attack. Suddenly a convoy escort named
Hayasaki closed and prepared to ram. As the small ship charged from the darkness, Gilmore sounded the collision alarm and shouted, "Left full rudder!" but to no avail. Perhaps inadvertently,
Growler hit
Hayasaki amidships at , heeling the submarine 50 degrees, bending of its bow sideways to port and disabling the forward torpedo tubes. Simultaneously, the Japanese crew launched a burst of machine gun fire at
Growler's bridge, killing the junior officer of the deck and a lookout, while wounding Gilmore and two other men. Gilmore ordered the men to clear the bridge as he struggled to cling to the frame. As the rest of the bridge party dropped down the hatch into the conning tower, the executive officer, Lieutenant Commander Arnold Schade, shaken by the impact and dazed by his own fall into the control room, waited for Gilmore to appear. Instead, he heard, "Take her down!" Realizing that he could not drop below in time if the ship were to escape, Gilmore's command meant that he was doomed. Schade hesitated briefly and then obeyed the order and submerged the crippled ship. Surfacing some time later to attack the
Hayasaki, Schade found the seas empty. The Japanese ship had survived the encounter, but there was no sign of Gilmore, who had drifted away during the night. Schade and
Growler's crew controlled the ship's flooding and voyaged back to Brisbane on February 17. For sacrificing himself to save his ship, Gilmore was posthumously awarded the
Medal of Honor, becoming the second man of the submarine force to receive the honor. ==World War II summary==