A K-class blimp in flight. On July 18, 1943, a U.S. Navy K-class blimp and a German U-boat engaged in a heated battle off the Florida coast. U.S. Navy photo

A close-quarters slugfest between a U.S. Navy blimp and a German U-boat lit up the sea and sky off the Florida coast on the night of July 18, 1943, and produced moments of remarkable heroism by American sailors.

The German adversary was the Type VIIC U-boat U-134, a 220-foot, 769-ton (surfaced) raider that had once torpedoed a German merchant ship by mistake but was now on her seventh war patrol, with Oberleutnant Hans-Günther Brosin as captain.

Blimp crews were expected to find the foe and call for help, rather than to use this skimpy arsenal to engage the heavy anti-aircraft armament of a U-boat directly.

K-74 was the designation of the 252-foot airship, piloted and commanded by Lt. Nelson Grills, USNR, with a crew of nine: Darnley Eversley, Ensign, USNR, navigator; John Jandrowitz, Aviation Pilot First Class, USNR, co-pilot; Isadore Stessel, Aviation Machinist Mate Second Class, USNR; Jonathan L. Schmidt, Aviation Machinist Mate Third Class, USNR; Robert Herbert Bourne, Aviation Radioman Third Class, USNR; John F. Rice, Aviation Radioman Third Class, USNR; Gerrold M. Giddings, Aviation Radioman Third Class, USNR; Garnet Eckert, Aviation Ordnanceman Third Class, USNR; and John W. Kowalski, Seaman Third Class, USNR.

K-74 was operating as part of lighter-than-air patrol squadron twenty-one (ZP-21) at Naval Air Station Richmond, Fla. A K-class blimp was typically armed with four depth charges and a .50-cal. machine gun mounted in the nose of the blimp’s gondola – but blimp crews were expected to find the foe and call for help, rather than to use this skimpy arsenal to engage the heavy anti-aircraft armament of a U-boat directly.

Shortly before midnight, the submarine surfaced and the crew threw open their hatches to vent carbon dioxide and take in fresh air. German sailors clambered topside to enjoy the tropical warmth. The U-134 was now in position to intercept two Allied merchant ships nearby.

K-74’s crew initially spotted the surfaced U-boat on radar, then emerged from cloud cover and made visual contact. The German submarine was on a direct course for the nearby merchant ships, and Grills was afraid that if he didn’t attack immediately, they would be sunk by the U-boat. Grills radioed to another blimp that he was pressing the attack.

Aviation Machinist’s Mate Third Class Garnet Eckert fired back with the gondola-mounted machine gun.

The submarine turned to port, and from the U-boat’s conning tower, 20 mm cannon fire rushed upward at K-74. The big and cumbersome blimp – readily visible in the moonlit night – initiated a bombing run at 250 feet of altitude. Aviation Machinist’s Mate Third Class Garnet Eckert fired back with the gondola-mounted machine gun.

As K-74 passed over the submarine, gunfire struck one of its engines. Grills’ radio operator got off an S.O.S. message. It appears today, in light of recovered documents, that Aviation Machinist’s Mate Second Class Isadore Stessel managed to drop two of the blimp’s depth charges.

The airship caught fire. The crew managed to defeat the blaze but fought to remain airborne as they slowly lost altitude, the blimp’s envelope shredded by enemy gunfire. The airship touched water in a high nose-up attitude, and the crew began to evacuate, wearing Mae West lifejackets.

Grills helped others escape, but remained behind to dump secret electronic gear and classified documents overboard. By the time he abandoned ship he had become separated from his crew. Many hours later he was rescued only when a crewmember of airship K-32 spotted him in the water, largely by chance. The remainder of the crew clung to the deflated bag of the blimp. At dawn, a J4F-2 Widgeon seaplane from ZP-21 discovered them.

Tragically, before he could be pulled from the sea, Stessel was attacked by a shark and vanished in a crimson froth.

The sea state would not permit the Widgeon to set down on water. The J4F-2 directed surface ships to a rescue. Tragically, before he could be pulled from the sea, Stessel was attacked by a shark and vanished in a crimson froth. As if in requiem, K-74’s two remaining depth charges – now underwater with most of the blimp – detonated deep below the surface. The USS Dahlgren arrived on the scene shortly after, and sailors armed with rifles and Thompson .45-caliber submachine guns fired shots to keep sharks at bay while the crew were brought aboard.

Initially, Grills and his crew faced official disapproval since they had violated standing orders in attacking the submarine, but this changed after the squadron commander interviewed them at length. It wasn’t until 1961, however, that Grills received the Distinguished Flying Cross and his crew Navy Commendation Medals, after German records revealed that K-74 had damaged the U-boat.

It is unknown whether the damage was severe enough to keep the U-boat from submerging, but in the hunt for U-134 after K-74 was shot down, the boat was damaged again in an air attack. It was finally sunk by a Royal Air Force bomber days later while attempting to limp home on the surface to Germany for repairs. K-74 was the only blimp downed by enemy action in World War II and Stessel the only crewmember killed by enemy action. Stessel’s family members did not receive his Purple Heart until 54 years after he died at sea.