Resurfacing the past
More than 20,000 ships sank during World War II. One man is on a mission to map them all — and is uncovering untold stories along the way.
Just off the island of Guadalcanal, in the South Pacific, a few rusty, jagged shapes protrude from the waters of Iron Bottom Sound.
This debris, visible by satellite, is what remains of the Japanese transport ship Kinugawa Maru, which sank November 15, 1942 after coming under artillery fire from U.S. forces defending the island.
The Kinugawa Maru was one of 50 Japanese and American ships that were destroyed during the Battle of Guadalcanal, the first prolonged engagement of the Pacific theater of World War II.
The array of ships that sank in Iron Bottom Sound, mapped here, testifies to the scale of the battle.
The waters off Guadalcanal were just one battleground in a years-long campaign, which spanned much of the Pacific Ocean and left behind constellations of sunken ships.
And the Pacific Ocean was just one theater of the war, which left virtually no corner of the global ocean untouched.
The seas were the most extensive — and often the most dangerous — battlegrounds of the Second World War. And the Kinugawa Maru’s story is fairly unextraordinary, from a military standpoint: Thousands of transport ships just like it were sunk over the course of the war. But for the people who served on that ship — and every other doomed vessel — its destruction was a cataclysmic, life-altering event.
The Kinugawa Maru, photographed in 1943. Photo: U.S. Navy
Peering into the deep
Stories like these are easily swallowed up by the vastness of the ocean and forgotten. But thanks to enterprising mapmakers like Paul Heersink, they are being preserved. Paul, a mild-mannered Program Manager at Esri Canada by day, has taken on the extracurricular task of mapping every sunken ship of the Second World War. Driven by personal interest, he has spent the past eight years combing through various primary and secondary sources, and vetting locations, dates, and causes, in order to create the most comprehensive dataset of its kind.
"[Some sources] had latitude and longitude, and some had a Google map with a pin for a single ship...so that made me think, wouldn’t it be good to put everything together on one map and see what kind of patterns there are?" — Paul Heersink
With more than 14,500 mapped records, the dataset unlocks new possibilities for analysis and visualization. And to encourage exploration and discovery, Paul has created a data-driven dashboard , which automatically updates as he adds new ships to the dataset.
This dashboard illuminates patterns and stories across all scales of the naval theater — from the fate of an individual ship like the Kinugawa Maru, to the arc of a particular battle, to the progress of the entire war. Some of these insights are featured below.
This animated map of Axis and Allied sunken ships shows how the naval theater unfolded over the six years of the war.
The Allied navies and commercial fleets suffered devastating losses in the first years of the war. But by 1943, the tides had turned in their favor.
There is a clear inflection point around March 1943: From this point onward, the Allied forces sank more ships every month than they lost.
The geography of naval combat evolved throughout the war. The Western hemisphere saw a gradual expansion, and then contraction, in the distribution of naval battles.
In the Pacific, meanwhile, the Allies’ island-hopping campaign gradually inched closer and closer to Japan.
Use the buttons below to filter the data by year.
By scaling the points to reflect the size of each sunken and ship, we can also locate the large-scale battles that shifted the tide of war.
The attack on , which drew the U.S. into the war, is brightly illuminated at the center of the Pacific.
Brighter still is the Battle of, the last major naval engagement in the Pacific, and the largest sea battle in documented history.
Meanwhile, the North Atlantic bears witness to the ill-fated showdown between the imposing warships , which led to their mutual destruction - and is considered one of the last head-to-head battles between large surface vessels.
Popular culture has immortalized the warships that engaged in these pitched battles. But in reality, most ships that sank during the war weren’t designed for combat. This map distinguishes between sunken and sunken.
Unarmed vessels like cargo ships, tankers, tugs, and floating hospitals played an outsized role in the conflict — and bore the brunt of the losses.
Thousands of Allied cargo ships were destroyed while crossing the . Many of these ships sank within sight of land, such as the oil tanker, which was torpedoed just five miles off the Florida coast. The ship was so close to shore, in fact, that its hull was illuminated by the lights from Jacksonville Beach.
Other hotspots for civilian ship losses include the waters off — at the time, one of the world's largest oil exporters — the , a key route into the Indian Ocean, and the , where Japan lost scores of cargo vessels in the closing stages of the war.
Putting the data to use
For data historians like Paul Heersink, this dataset helps illuminate the magnitude of the war, its nuances, and its impact on a human level. But it has practical purposes, too. Sunken ships are often laden with fuel and munitions, and can pose a threat to marine ecosystems and passing vessels. A comprehensive record of WWII shipwrecks could aid in ongoing containment and clean-up efforts around the world.
A recent project in Serbia, for example, led to the removal of some 23 WWII-era wrecks from the Danube River — but hundreds more litter the heavily trafficked waterway. In the U.S., the National Oceanic and Atmospheric Administration (NOAA) has located dozens of hazardous WWII shipwrecks off the Atlantic coast; this dataset could be used to document even more wrecks.
There are also economic incentives for locating these ships, as they contain valuable materials. Notably, the steel found in many WWII shipwrecks is uniquely useful , because it predates (and was insulated underwater from) the first atomic bomb tests. As a result, this steel has exceptionally low levels of radiation compared to newer steel, and is useful for particle-physics experiments.
These practical applications aren't just hypothetical: The dataset is already being used to support environmental assessments for offshore wind energy projects, and additional research groups have expressed interest in applying the data to their own studies.
Carrying the past into the future
As the Second World War recedes into the past, and the number of surviving veterans dwindles, it is increasingly difficult for people like Paul to compile a thorough account of events.
While there is an established community of shipwreck aficionados that Paul can turn to for guidance, he is sometimes forced to rely on official maps and logs, which can be incomplete or fraught with inaccuracy.
“Any navy is usually pretty good about tracking where its ships are, but in times of crisis, the first thing on someone’s mind might not be ‘we need to [record] an accurate location’ when they’re being chased or bombarded.” — Paul Heersink
The process of verifying ship locations can be especially frustrating, Paul admits. But he also relishes the challenges of digital forensics, like comparing archival photographs with present-day aerial imagery to pinpoint the exact location of a wreck.
Paul Heersink, the man behind the data.
While Paul's patience and perseverance are laudable, he is quick to point out that anyone can pursue such data projects, regardless of technical or subject matter expertise.
The dataset remains a work in progress , and Paul acknowledges that it's far from complete. He's slowly working through a backlog of nearly 5,000 partially documented, trying to piece together these ships' stories before they disappear for good. But he has no intention of stopping now, and continues to update the dataset each week.
After eight years of mapping, Paul is surprisingly modest about his accumulated knowledge; “I’m not a historian,” he insists. But that’s a big reason why he has shared his work publicly: so that anyone can explore it and reach their own conclusions.
So what are you waiting for? Dive into the map below, or check out Paul's dashboard — you never know what stories you might uncover.
Explore this interactive map of all sunken ships of WWII.
