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Shearwater Predator and Heinrichs Weikamp OSTC 2N
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Noel Hitchins 1951-2005
Lloyd Bridges - Mike Nelson in Sea Hunt
My Yachting Adventures
Below is a list of links to the main pages about my yacht, Catlypso and My Yachting Adventures:
  • Purchase of Catlypso
  • Details about Catlypso
  • Cleaning/Repairing Catlypso
  • My Yachting Adventures.
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    Michael's 4WD Trips
    Click here for a list of my Four Wheel Drive and Camping Trips.
    Home Brewing
    Click here for an article about Home Brewing.
    Sydney Dive Site Hints
    "There are two Manly Ferries that can be dived off Sydney, SS Dee Why and SS Bellubera"
    Mitsubishi G4M "Betty"
    Michael McFadyen's Scuba Diving - "Betty" Bomber In 1938 the Japanese Navy put out a specification for a new bomber. The result was the Mitsubishi G4M, nicknamed Betty by the Allies. (Note: The Japanese designation G4M means G=Attack Bomber, 4=4th in the attack bomber series, M=Mitusbishi). This was the premier Japanese bomber of the Second World War with 2,479 being built by Mitsu1bishi Jukogyo KK.

    The plane was powered by two 1,850hp Mitsubishi Kasei 22 14 cylinder two-row radial engines (the company tried to talk the Navy into four engines) with a wing of 24.9 metres and a length of 19.6 metres. The plane was armed with one 7.7 mm gun in the nose, 20 mm guns in the tail and each beam window. It carried an internal bomb load of up to 1,000 kg or one external 800 kg torpedo.

    Betty bomber
    Mitsubishi G4M1 "Betty"

    The Betty was capable of a maximum speed of 455 km/h with a range of up to 5,000km, depending on actual model. Unfortunately, as the plane was totally strained by the load being carried and only powered by two engines, the aircraft was almost totally without protection. This meant that when hit by flak or bullets, the plane inevitably caught fire and crashed. This led to another unofficial Allied nickname of one-shot lighter or Flying Cigar.

    When the Japanese started fortifying Chuuk (Truk) Lagoon in the middle of the Pacific Ocean, they almost demolished the island of Eten by bulldozing one half of it into the lagoon and building a runway. When completed, Eten Island resembled a giant aircraft carrier, with the runway looking like the deck of the ship and the remaining hill looking like the bridge of the carrier (there are some really interesting buildings on Eten and you used to be able to examine them during your lunch break on the island - not sure about now).

    Betty bomber
    The Mitsubishi G4M1 "Betty" from above

    One of the Betty's engineThe nose of the Betty
    One of the Betty's engineThe other engine of the Betty
    Note the tip is not bent
    The Betty's enginesThe nose of the Betty
    Dive guide Keran and the two enginesThe nose of the Betty
    From video taken 1997

    There is a wreck of a Betty bomber right off the end of the Eten Island runway in 15 metres of water. The plane is located at GPS Reading of N7° 21, 6.6" E151° 52' 42.1" using WGS84 as the datum. This will put you on a mooring which is right on the wreck.

    The plane is about 300 to 400 metres from the island. The plane appears to have crashed on take off, possibly from engine failure or during a very aborted landing, possibly running out of fuel. I came to this conclusion because of the following reasons:

  • The plane's engines are located about 75 metres closer to the island than the body and wings of the aircraft proving that the plane was travelling away from the runway.
  • Being heaviest, the engines fell off as soon as the plane hit the water and the plane kept on going forward.
  • The plane dug in by the starboard wing and spun to the right and ended up facing back towards the engines (this is confirmed by the engines being on the opposite side of the plane now to where they should be and the starboard wing having now broken off at the tip).
  • The propeller blades are not bent back at the ends proving that the engines were not running when the plane hit the water (when a plane hits the water with its engines running, the very tips of the props are bent backwards by the force of the water).
  • Betty BomberBetty Bomber
    The port wing of the BettyThe nose of the Betty
    Taken 2011
    The Betty's enginesThe nose of the Betty
    The dorsal gun turret (left) and observation hatch (right)The observation hatch

    The plane is almost intact, but the nose is quite damaged, with the window frames badly bent. In fact, between 1997 and 2011 the whole nose has totally broken away from the main fuselage. The wings are in one piece apart from the tip of the starboard wing being broken off and as mentioned, the two engines are missing. In fact, as indicated above, they are located about 75 metres away between the plane and the runway.

    In addition, the tail of the plane has broken off and is lying on the sand behind the plane.

    The only obvious damage from being shot down are a number of holes on the main fuselage which appear to be bullet holes as they come from inside (see the attached photograph).

    One thing I noticed is that the tail elevators are slightly up. This means that at the time the plane crashed, the pilot was attempting to climb. The flaps on the main wings though are not down, meaning that the plane was not attempting to land or take-off.

    Betty BomberBetty Bomber
    Inside the forward section of the fuselage
    looking towards the waist gunner positions
    Looking forward inside the fuselage towards the cockpit
    Betty BomberBetty Bomber
    Kelly inside the rear section of the fuselageI am pretty sure that this bullet hole is
    one of a number on the top of the fuselage

    The fuselage of the plane can be entered from the front or either of the gunners' bays towards the rear. Swim along from the rear and you will see the side gunners' positions, the radio compartment and then the cockpit. You can exit through the cockpit windows if you are careful.

    Once outside, an interesting thing to do is open the observation window behind the cockpit. Amazingly, after more than 65 years it still opens easily.

    There is one gun lying on the port wing (it is from one of the side gunners' bay) and there are some items like radios, batteries, oxygen cylinders, the pilot's seat and other bits on the sand around the wreck. There is even a toilet here.

    Betty BomberBetty Bomber
    The rear of the plane - note the tail on the bottomThe tail elevator is up a little
    Betty BomberBetty Bomber
    A toilet, oxygen cylinder or extinguisher and other itemsThe pilot's seat on the sand

    This is an interesting dive. It is usually done as a pair with the nearby "Emily" Flying Boat. You do the first half of a tank on this plane (about 20 minutes) and then travel the short distance to the "Emily" where you use the rest of your cylinder. It is usually done as the fourth dive of the day if you are diving from the SS Thorfinn. If this is your first trip to Chuuk (and/or you only have a few days there), I would not give up a dive on one of the shipwrecks to dive this plane.


    Video shot by Kelly McFadyen during our 2011 trip to Chuuk.

    3D Computer Model

    Click here to see a 3D Computer model of the plane by the Truk Lagoon Baseline Project. Very cool.


  • 16 November 1991
  • 14 November 1997
  • 31 October 2011

    Additional Photos

    Photos by Shaun Reynolds taken March 2013.

    Betty Bomber
    Looking forward from behind the tail on the port side

    Betty Bomber
    The Betty bomber from high above it


  • Bombers of World War II by Bill Gunston
  • Jane's Fighting Aircraft of World War II
  • Hailstorm Over Truk Lagoon by Klaus Lindemann
  • WWII Wrecks of the Kwajalein and Truk Lagoons by Dan E. Bailey

    Photos taken from Hi8 video footage

  • Copyright © Michael McFadyen 1990 to 2024
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    This web site has been wholly thought up, designed, constructed and funded for almost 30 years by Michael McFadyen without any help from the Australian Dive Industry.
    Website created 1996!