Monday, July 19, 2010

Lost in Plain Sight: GIMIK and OSS Project NAPKO

This was one of World War Two’s longer-running mysteries, finally solved. This is one of a pair of two-man submersibles that were designed and built for the OSS (Office of Strategic Services, the U.S. wartime intelligence agency) in Connecticut in May, 1945. Code-named “GIMIK,” these vessels were the infiltration assets for a clandestine operations program devised and headed by Colonel Carl Eifler called Project NAPKO. NAPKO’s purpose was to recruit and train 55 Korean Americans and Korean Prisoners of War for infiltration into Japan to collect intelligence and conduct sabotage in advance of Operation Olympic, the planned U.S. invasion of the Japanese home islands in late 1945. Korean POWs were targeted as Korea was at that time under Japanese occupation, and Colonel Eifler correctly believed that Korean nationals who had been inducted into the Japanese military, and then captured by U.S. forces during the Pacific campaign would be inclined to turn against their colonial masters in order to help shorten the occupation of their country.
NAPKO’s original plan called for three boats, however only two were actually built, costing $20,000 each. Gimik had an operating radius of only 110 miles, and was intended to be transported to its destination by a mothership to a point off the enemy coast, and then take its operator and a single infiltrator passenger ashore. When operating in the infiltration mode, the craft ran as a semi-submersible with its deck awash until reaching a point close to the landing area. Upon arrival at this point, the crew would submerge the empty vessel to a depth of up to thirty feet, where it could remain underwater for a period of up to three to four weeks while its crew was ashore carrying out their mission.
The two GIMIK boats were delivered to the OSS on June 10, 1945. Following delivery, they were used to train Project NAPKO crews at the OSS training facility at Catalina Island, off southern California over the summer of 1945. NAPKO’s Korean operatives repeatedly penetrated the harbor defenses of both Newport Beach and Los Angeles undetected, as well as landing agents at Newport Beach and San Clemente during their operational workups.
Preparations to execute NAPKO continued until the scheduled departure date of August 26, when Col Eifler and his teams were to depart for their overseas base, probably located at Kerama Retto, Okinawa. In summer 1945, Okinawa was the closest Allied-held territory to Japan; Kerama Retto had served as a base for both Japanese Army and Navy explosive suicide boat units. Following occupation, Kerama Retto served as a major advance support base for Allied forces in preparation for the upcoming invasion of the Japanese mainland.
After arrival at Okinawa, Eifler and his Korean agents would board a US Navy submarine and rendezvous off the coast of Japan with GIMIK and its mothership, which had been previously staged at Okinawa for the operation. At the rendezvous point, Eifler and another agent would board one Gimik boat, and presumably another pair would board the other boat. Japan’s surrender announcement on August 15, of course, put an end to NAPKO’s deployment.
With the end of hostilities, Gimik was forgotten and left in storage for a number of years, until it was found in 1972. Based on a magazine article from the mid-1980s, it was originally thought that the boat was found in Okinawa, however, recent research leads us to believe it had been in storage at the U.S. Naval Base, Newport Rhode Island. Because of its odd configuration, and a complete lack of documentation, it was thought to have possibly been a captured Japanese suicide boat, albeit one that really didn’t match the major Japanese types. The boat was restored and placed on display in the PT Boat collection at the Battleship Massachusetts, where it was displayed as possibly being a Japanese suicide boat, but heavily caveated with the fact that nobody really knew its identity. GIMIK remains on display at Battleship Cove to this day, now finally definitively identified.

Specifications and Technical Description:
Builder: Not definitely identified, but likely Electric Boat Company, Groton Connecticut
Length: 19 feet, 2 inches
Beam: 5 feet, 3 inches
Height: 6 feet, 9 inches
Weight: 3,650 lbs.
Engine: Gray Marine 4-cylinder gasoline type with Autolite spark plugs

Speed: Awash: 4.7 knots, Surfaced: 4.1 knots
Economical: 2.5 knots
Range: 110 nautical miles
Crew: 2-3
Cargo: 110lbs of equipment

The engine is sealed in a large steel pipe with an access hatch in the upper surface. The forward end of this pipe forms part of the aft crew compartment bulkhead. The fuel tanks are aft of the engine, while a small stack aft of the cockpit provides both air intake and exhaust for the engine. The large tube forward of the cockpit is the air intake for the crew compartment. The air pump is operated from a 3-belt V-type drive attached to the propeller shaft. Trim tanks are located at each end of the boat and can be operated while underway, the boat being designed to run awash. A muffler, by Maxim of Connecticut, is installed for quiet operation, and the cockpit is covered with a well designed hood of 3/8 in plexiglass. There are four small compartments in the bow and what appears to be piping running aft to the cockpit.

Photos: (top), Col Eifler's bio, The Deadliest Colonel (lower)


  1. I keep rereading this, very informative.

  2. Is this where they got the idea from the Narco boats on the other page?
    They look similar in some respects, but I'd have to do a side by side comparison.

  3. All documents and books I've read regarding NAPKO refer only to Korea, not Japan. So I suspect that the Gimik submersibles were for the penetration of Korea, not Japan.

  4. @Prof. Conundrum

    Sorry, I have to respectfully disagree, A report written by Colonel Eifler, OIC of the Field Experimental Unit to OSS Director Donovan stated that the NAPKO project was aimed at getting the Koreans ready to penetrate into Korea anytime and then go into Japan to form an underground organization to launch sabotage and non-resistance movement.

    A five-second internet search turned up this from the Winter 2008 edition of the OSS Newsletter:

    South Korean Broadcast System
    Seeking Info on OSS/Korean Ops
    Th e K o r e a n B r o a d c a s t i n g S y s t e m ( w e b s i t e is preparing a special documentary for Korean Independence Day in August. The subject is The Napko Project, a clandestine operation under OSS during WWII which trained POWs to be deployed in Japan for disruption.

    The producer/researcher of the documentary is seeking anyone who was in the field experimental unit at the Santa Catalina training camp; anyone who was on the recruiting team to select the Korean agents; and anyone who remembers the program and would like to be interviewed on camera.

    The boats, being boats, could be used anywhere. If you have authoritative documentation that the target wasn't Japan, I'd certainly be interested.


    I don't think so; GIMIK is much more robustly constructed than the SPSS drugrunners. I think it's really a case of form following function.


  5. GIMIK: Father of the CIA Skiff?
    I am researching for a story on the CIA Semi-submersible Skiff built in 1953. My father ran the project and I recently received material from the CIA regarding it. From all that I see here, the CIA version is CLEARLY a later modification of GIMIK. With whom may I connect to share information?

  6. @Adriaticus Yes it was for the eventual penetration of Japan, but we were discussing the submersible, not NAPKO, correct? Do you think the submersible was going to be later dragged to Korea's east coast for an assault on Japan? I was only saying that the submersible was to deliver men TO Korea,not FROM Korea TO Japan.

    1. @photografr7: Huh? No, I don't think it was going to be dragged from Korea to Japan. We're discussing both NAPKO and the submersible. My current understanding of NAPKO is that the intent was for Korean-born agents to penetrate mainland Japan.

  7. Can anyone confirm that NAPKO stands for "Naval Penetration of Korea"?

    1. @photografr7: No, I can't but it would seem a logical expansion of the acronym. I'm not done researching the topic though.

    2. BTW, @phtografr7 and @Prof.Conundrum, you appear to be the same individual.

  8. Hello .... I am the son of George McCullough. He is now 87 and was one of the two ensigns who were to captain the vessels for this clandestine OSS mission. I have all of the details for whoever is interested. His story is fascinating. I can be reached at and he can also be reached if necessary. Some of your information is correct, and some is not. The vessels went by the names of "Gizmo 1" and "Gizmo 2". My father interviewed in NY with Col. Eifler, but otherwise the Col. didn't have much to do with the training, etc. Let me know what questions you may have ! Thanks, Mike McCullough

    1. Thanks, Mike, I'll be emailing you today. I am most definitely interested!

    2. Hi Mike
      My name is Rick Hunt, im an avid collector of navy diving gear and insignia from the turn of the century till Nam era. I recently acquired a WWII CPO dress jacket with a master diver insignia, inside on the owners label it has the name McCullough, but no initials. I am trying to ID the original wearer and was wondering if it might have been your dad's. I bought it from a dealer in the Philadelphia area. I'd be happy to send you pics if you like. The speciality on the cooling rating is one of the emergency ratings used in the latter half of the war, " R" for recruiter. Any help would be greatly appreciated, thanks so much
      Rick Hunt. St Pete Fla.(deadpeoplesjunk@

  9. It may interest you to know that the Korean Government published all the NAPKO documents they could find in American archives under the title NAPKO Project of OSS:재미한인들의 조국 정진 계획. All of the documents are in English and are available online at:

    A bound version also exists and can be found in some libraries.

    1. Thanks very kindly! I also learned about NAPKO Project of OSS about a year ago myself, and found the online version, but haven't been able to find a bound version for purchase as of yet.

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