One of the stranger missions to come about during World War II was the decision to infiltrate the Korean coastline, which was then held by the Japanese, and insert former Korean POWs into the country to set up agent networks, conduct sabotage and possibly begin a guerrilla war against the Japanese. Eventually, the plan was to infiltrate the coastline of Japan itself.

Code-named Operation NAPKO, it was headed by the Office of Strategic Services (OSS), the forerunner to both CIA and the U.S. Army Special Forces. Operation NAPKO was run by Colonel Carl Eifler, the larger-than-life OSS operator, who was the first commander of Detachment 101 in Burma that recruited and trained the Kachin Rangers.

The plan was to use a semi-submersible boat, code-named the GIMIK, to shuttle 10 teams (each comprised from one to five personnel) of Koreans onto the coastline where they would use their own contacts to set up agent networks. The former POWs would choose their own infiltration points due to their personal knowledge of the operational areas. The agents would then set up radio communications with U.S. listening posts in Manchuria and the Philippines.

The 55 Koreans selected for the mission were given extensive training by OSS and each of the teams were kept separate and unknown to each other. That way, in case of capture, they wouldn’t be able to relay anything of importance to the Japanese.

Eifler hoped to have at least seven of the teams operational and the ones who showed the greatest progress would be exploited to the maximum potential. According to CIA archival information, only two teams progressed enough to get to the operational planning stage. 

“Code-named ‘Kinec’ and ‘Charo.’ Both were very similar in concept, differing primarily in intended points of penetration and operating areas. Kinec envisioned landing five agents at Chemulpo Bay, about 20 miles outside Seoul on the country’s west coast; Charo was focused on Pyongyang following penetration via Wonsan and utilized three, rather than five, Korean agents. Typical of NAPKO missions, the teams were to carry minimal equipment and supplies: 100,000 yen, a radio, appropriate clothing for passing as locals, and a Japanese-manufactured shovel for burying the team’s equipment after landing.”

The method of infiltrating the teams into Korea was to transport them on a submarine and then launch the GIMIKs off the deck of the sub in order to ferry the teams ashore. The GIMIK was manufactured by John Trumpy and Sons of Camden, NJ, who were well-known yacht builders on the East Coast. The cost of the boats in 1944 dollars was $26,000 for each of the GIMIKs. That would translate to just under $270,000 today.


Originally OSS asked for three GIMIKs, but only two were ever built. They were nicknamed the Gizmo 1 and the Gizmo 2 by their operators. The Navy selected two junior officers to pilot the craft, Ensign George McCullough and Ensign Robert Mullen. The men went through intensive OSS training at Catalina Island off the coast of California to prepare themselves for the mission. 

The boats were 19 feet long and manufactured out of plywood to frustrate any radar or sonar detection devices. They were designed to ferry two agents and one boat operator and up to 1000 pounds of equipment. The GIMIK had a range of about 100 miles and could operate on the surface, semi-submerged or fully submerged. During infiltration, the boat would be in the semi-submerged mode with the decks awash until reaching a point close to shore. The snorkel was wrapped in steel wool to reduce the radar signature. Finally, the operator had a small plexiglass screen that was used to see what was ahead of the boat. 

George McCullough with the GIMIK submersible that he trained on during WWII to infiltrate Korean waters.

The boats would be transported by submarines in large metal boxes called “coffins” by the crew. Then once in the operational area, the boats would be launched by the mothership. 

The crews practiced infiltration in the Los Angeles harbor and were successful in approaching the shore undetected. The plan was to fully submerge the vessel, once the team was safely ashore, where it could remain anchored to the bottom to reduce detection for up to four weeks.   

The first NAPKO teams were to launch from Okinawa into Korea on August 26, 1945. However, the dropping of the atomic bombs on Hiroshima and Nagasaki ended the war on August 15 and the plans were scrapped. Which is probably a good thing for the teams that were involved: The chances of success for this operation were dubious at best. 

Although the Koreans hated the Japanese, who treated them as second-class citizens, Korea was occupied by the Japanese since 1905. The Japanese were firmly entrenched in Korea and the police force and military there would have cooperated with Japan.

The boats were turned over to the Navy, which didn’t know what to do with them. They were then abandoned on a naval base.

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Later, during the Cold War, the CIA dusted off the GIMIK concept and built a very similar craft called the SKIFF to be used to ferry Cold War agents ashore in denied countries. However, that plan was never implemented either. 

An interesting footnote to the GIMIK is that both boats still exist today. One is on display at CIA HQs. The other is on display at Battleship Cove in Fall River, Massachusetts. For several years it was incorrectly displayed and identified as a Japanese suicide submarine. It wasn’t until a CIA employee saw the display on a visit to Massachusetts and, recalling the vessel at agency HQs, put two and two together. 

McCullough is still alive at 97 and lives in a veteran’s living-assisted community in Houston. He gave an interview with KHOU 11 television on his memories of the mission for which he was trained, but never able to conduct.

Photos: George McCullough/CIA/Battleship Cove, Video: Courtesy of KHOU 11