On 17 and 18 February 1944, American forces attacked what has become one of, if not THE wreck diving mecca in the world – Truk Lagoon. This lagoon in Chuuk atoll arguably offers the world’s best wreck diving. This weekend is the 80th anniversary of Operation Hailstone, which is reason enough for us to dedicate a week on our social media channels to seven of the wrecks.
Why Dive Chuuk and Truk Lagoon?
There are about 60 or so reasons (read wrecks) that make Truk Lagoon one of the places offering the world’s best wreck diving.
If you’ve been following us for a while, you’ll know that we just can’t stop talking about the awesome shipwrecks divers can visit here. Starting from very shallow wrecks where parts are suitable for snorkeling in calm seas and stretching well beyond 60 metres, this area has something for almost every level of diver.
How Did the Wrecks Get There?
During World War II, these islands were occupied by the Japanese. Even before the war, Japanese forces had started fortifying the islands. Now, before I write anymore, I should give credit where credit is due: much of my knowledge about the area comes from Rod Macdonald’s recently updated book, Dive Truk Lagoon (2nd edition), available directly from the publisher or on Amazon. I loved having the PDF version as a guide with me on the December 2023 trip.
But let’s get back to history: Truk became a supply base for the Imperial Japanese Navy’s (IJN) Combined Fleet one month before the attack on Pearl Harbor. From 1942 until 1944, this lagoon was the main forward naval base for the fleet. Until early 1942, the Japanese had dominated the war in the Pacific. However, as the Allies launched their own offensive, Truk came under pressure. The Japanese rushed to fortify the atoll as the Allies moved closer.
By early February 1944, two US Marine reconnaissance planes flew over the area, remaining undisturbed for a full 20 minutes of taking pictures of fortifications. The Japanese knew that an attack was likely imminent and started moving battleships and other fighters away from the base. As soon as U.S. High Command received the images, the attack was moved forward from a planned April date. Operation Hailstone commenced before dawn on 17 February 1944 and continued for two days in the air and at sea.
The Wrecks Today
Many of the main Japanese fighting force had left by the time of the attack, which means many of the shipwrecks you dive today are merchant ships that carried supplies for the military. If you’d like to know more details, I recommend Rod’s book, but a Google search will also yield a lot of information.
Following on from our Facebook and Instagram countdown, here is a closer look at seven of the wrecks.
#1 – Kensho Maru
This wreck is famous for having one of the most astounding engine rooms you could ever wish to dive. It’s certainly a ‘must’ on any Truk Lagoon trip. Not only are there plenty of gauges still to be seen, but the entire space is large and cavernous and mostly intact.
It’s also easily accessible through multiple entry and exit points. Even if more serious wreck penetration and small spaces are not that high on your list, consider dropping through the engine room skylights in 20 m into the massive space below that’s 10 or more metres high. It makes for iconic pictures, too.
If you do decide to swim into smaller spaces, you’ll be rewarded with tools, gauges and countless other details that will have you reach for your camera.
#2 – Sankisan Maru
Get ready to find bullets strewn all over this wreck or at least its relatively intact forward section. Like so many others in the lagoon, this former passenger ship was carrying vast quantities of ammunition.
Diving Sankisan Maru is almost a tale of two dives. Her forward section sits relatively shallow in 24 metres of water. the bow remains upright and, with the right light conditions, can make for an impressive image. Divers can still find the remains of Army trucks on the deck and aircraft engines in one fo the holds. And bullets, they’re all over the wreck.
The wreck was largely destroyed behind the bridge, leaving its rudder, propeller, and a part of the keel lying separated from the rest of the wreck in 45 metres. Divers have a choice of concentrating on the shallower part or heading deeper to see what remains of the stern before returning for their decompression stops.
For those of you who love seeing colorful tropical soft coral, it’s worth spending your decompression stops or the shallower part of the dive around the king post in the bow section. Because of its shallow depth and light penetration, coral has taken over this area.
#3 – San Francisco Maru
Does this wreck even need an introduction? Lying in 45 to 63 metres, the San Francisco Maru has everything divers need for a dive lasting several hours. There are holds stuffed with tanker trucks and a staff car, spherical mines, cordite, shells, 50lb bombs and aircraft engines.
The deck itself is worth spending time on to see the well-preserved Ha-Go tanks in front of the damaged bridge superstructure. They are certainly worth stopping on for a picture. There is also a well-preserved bow gun on a skeletal platform standing up from the bow.
Further toward the stern, divers can access the engine room and explore holds three to five. At this stage, you need to be careful not to get carried away and overstay your welcome. There is far too much to see here for only one dive. Saying that, because of the depth and the rather long dive many divers complete here, diving the San Francisco Maru often makes for a single-dive day.
#4 – Betty & Emily
Did you know that there are airplane wrecks in Truk Lagoon?
Betty & Emily are two of the shallower dives, and they’re smaller than many of the shipwrecks. That’s why they’re easily combined into one afternoon dive that won’t take you beyond 20 m.
There is plenty to see and do still – swim through an airplane, marvel at the details of the plane parts and how much they’ve become part of the reef already. Although you can clearly see the outline of the plane as you descend, both wrecks have taken serious damage, and parts like the seat have been thrown out of the actual body of the plane.
#5 – Nippo Maru
Nippo Maru slid down a nearby reef, which the stern of the wreck still sits against. With its holds full of ammunition and plenty of things to see on the deck, this 45-50m wreck is another one where it’s easy to rack up considerable decompression obligation. Luckily, the bridge of the Nippo remains relatively intact and makes for an ideal place to explore while clearing that deco obligation.
What else is there to see? On the deck alone, divers will find Howitzer guns, a Ha-Go battle tank, and the remains of cargo trucks. That is before you even head for the holds and explore what kinds of ammunition the Nippo Maru was carrying. But back to the bridge: it’s easy to access through its former windows, and the helm telemotor as well as the engine order telegraph remain intact. Both make for excellent image subjects.
#6 – Shotan Maru
One of the smaller wrecks in the lagoon, the Shotan Maru remains largely intact, sitting in 51 metres of seawater. Aside from being called Shotan, the wreck had two other Kanji / Japanese names, potentially causing some confusion for historians. Divers today know this wreck as Shotan Maru.
Because of its smaller size, it can feel easier to grasp the entire wreck on one dive. The Shotan carried bottles, rolls of steel matting and grenades as well as other ammunition, and divers can still explore them by swimming under the main deck from hold 1 to hold 2.
Hold 2 is home to beer bottles, a diesel engine and a wheeled compressor. Odd combination? Perhaps not if you were restocking naval forces.
#7 – Momokawa Maru
Momokawa Maru is another highlight on any Truk itinerary, albeit one that never quite reached star status. Like Nippo Maru, Momokawa’s bridge remains largely intact with an impressive engine order telegraph to admire.
What else is there to explore? At a maximum depth of 42 metres, plenty of divers will get a significant amount of time to explore here. Take a moment to marvel at how the entire wreck looks almost undamaged. (You need to look a little closer toward the stern section to identify the bomb damage that sunk this wreck.
In the forward holds, divers can explore trucks, aircraft parts and fuel drums. Moving past the bridge and further back, you’ll recognise the engine room skylights. They tend to be open, making it easy to take a look at the steam engine inside which remains surrounded by walkways, staircases, and plenty of panels and gauges to discover.
Want to Know More?
Check out our YouTube channel. There are a few videos there already, and we’re adding more all the time. Plus, there is also a video with our top ten Truk Lagoon questions and answers that help you get a better idea of what a trip to the world’s best wreck diving could be like.