Kev Kelly

Subs have been an interest of mine for years and when I heard there was one at Chuuk Lagoon, I was keen on diving it. While the rest of the crew headed off to explore a freighter, my brother Brendan and I had the other boat to ourselves on the short trip to the I169 site. Japan built the largest subs of World War 2, in fact they were not exceeded in size until the advent of nuclear subs. The I class vessels were almost 350 feet long and could carry aircraft and mini subs. The midget sub attack on Sydney harbour was launched from this type of sub.

The I169 sank during one of the US bombing raids, but the Yanks didn’t sink her. She headed out into the lagoon to submerge and wait out the raid on the bottom. Somehow the main induction valve, which feeds air to the diesel engines when the sub is on the surface, was either left open or failed to close properly, a not uncommon occurrence apparently. As the sub dived, thousands of litres of water poured in through the valve and the I169 settled on the bottom without enough positive buoyancy to overcome the excess water on board.

Many of the crew drowned in the flooded parts of the sub but others were still alive for some time as divers could hear tapping on the hull. Attempts to raise the sub failed and the remaining men perished. Not wanting the sub to be salvaged by the Americans should they invade Chuuk, the Japanese depth charged it and totally wrecked the forward part. It is a colossal mess of mangled steel and only the aft section is intact, which is a shame because diveable subs are rare.

At 38 metres there is limited bottom time and a good deal to see. The wreck has a lot of coral and marine life and a large shark swam by as Brendan and I were exploring it. The first stop is a small hatch on the deck. I’ve heard of divers removing their tanks and going through this hatch but they are taking a huge risk. This is the only penetration point on the sub as far as I’m aware. Travelling down the port side we reached the stern where one of the propellers is visible. With our deco time increasing we couldn’t hang around and continued up the starboard side of the sub and back to the middle. Unfortunately the conning tower is nothing but scrap and unrecognisable. The damage caused by the depth charging is phenomenal.

The I169 is not one of the popular wrecks at Chuuk but it has an interesting and well documented history and this makes it worth a visit. I’ll be looking to dive this wreck again on my next trip to Chuuk.