You probably learned about the USS Arizona in grade school. I doubt anyone mentioned she’s still leaking.<\/p>\n
Visitors at the memorial over the wreck can look down and see it, a slow trickle of fuel oil that rises a few drops at a time and leaves a thin sheen on Pearl Harbor. People call those drops the “black tears,” and I doubt anyone’s going to come up with a better name. The 85th anniversary of the attack is a month away, so I went through what the government and the scientists have published about that oil. There’s a lot more of it down there than I’d assumed, and it hasn’t changed nearly as much as you’d expect.<\/p>\n
So why has no one gone in to get it?<\/p>\n
We’ll get there, but you need to know what’s sitting on the bottom first. The Arizona’s a Pennsylvania-class battleship, 608 feet long, with a displacement of 31,400 tons in the Navy’s official history. Displacement is basically a ship’s weight. You get it by working out how much water the hull pushes out of the way. She picked up extra armor in a rebuild that wrapped up in 1931, so I’d guess she weighed more than that on her last morning.<\/p>\n
On December 7, 1941, a Japanese bomb of about 1,760 pounds glanced off one of her forward turrets, punched through the deck and set off a powder magazine. The blast killed 1,177 of the 1,512 men aboard, and the ship was on the bottom within nine minutes, according to the National Institute of Standards and Technology (NIST). One of the dead was Rear Adm. Isaac Kidd, the namesake of the destroyer that’s waiting on the Mississippi to rise so she can go home to Baton Rouge<\/a>.<\/p>\n More than 900 of those sailors and Marines are still inside her, according to the Navy. Some of the men who survived have joined them, too, because since 1982 the Navy has let Arizona survivors have their ashes placed in the ship by divers. Keep that in mind for everything that follows, because it pretty much decides the answer to that question.<\/p>\n She’d just filled up. Chris Reddy, a marine chemist with Woods Hole Oceanographic Institution (WHOI), told Phoenix public radio station KJZZ last December that the ship took on a full load the day before the attack and had about 1.6 million gallons aboard. You’ll also see figures around 1.5 million in other accounts, and I couldn’t find a primary document that settles it.<\/p>\n A big chunk of that went up in the fires, which burned for two days, or spilled into the harbor. As for what’s left, a 2016 dive write-up from the National Park Service says about half a million gallons remain in the stern, while WHOI’s October 2025 release<\/a> says about 600,000.<\/p>\n There’s no dipstick on a sunken battleship, so both of those are estimates. A 2018 Coast Guard Academy release says she’s in 26 feet of water with another 30 feet of mud under that, which is a big reason no one can go look at the lowest parts of her. Reddy thinks a lot of the oil is down below the mud line, too.<\/p>\n Here’s where it gets a little fuzzy. Reddy told KJZZ the ship leaks about a gallon or two a day. That Coast Guard Academy release put it at about half a gallon. As far as I can tell, the Park Service doesn’t publish a current official number, so you’re basically picking from a range of estimates.<\/p>\n You can watch it come up through several parts of her deck, the Park Service says. How it gets there is anyone’s guess, though, since the Coast Guard Academy said in 2018 that no one knew where inside the ship it’s leaking from.<\/p>\n A gallon a day would be a pretty alarming leak on your truck. It’s a lot less dramatic in a harbor, and Reddy said in WHOI’s release that the wreck is “not leaking at a highly concerning rate.”<\/p>\n I ran the math on that, because I couldn’t help myself. At 2 gallons a day, 600,000 gallons would take about 820 years to seep out. At 1 gallon a day, it’s about 1,640. The steel won’t last that long, going by NIST.<\/p>\n Back in 2006, two NIST scientists, Tim Foecke and Li Ma, modeled the middle of the ship on a computer and ran decades of saltwater corrosion on it. NIST says<\/a> Foecke figures the hull has another 100 to 150 years until it’s completely collapsed, and the Coast Guard Academy credits the Park Service with that range as well. So you and I probably won’t be around to see it.<\/p>\n Coast Guard cadets hung steel samples on the hull in 2018 to help tighten that estimate up. I’ve found a 2020 conference abstract on that work, but no new number for the hull.<\/p>\n This is what surprised me the most. Spilled oil usually gets chewed up pretty fast, because the light stuff evaporates and microbes eat a good share of what’s left. Reddy told KJZZ that on other spills, “we have seen more degradation in six weeks than the 80 years” he’s seeing here.<\/p>\n His explanation is basically packaging. Most of the fuel’s still sealed up in tanks way down in the ship, with hardly any oxygen and not much fresh water moving through. He compares it to a fish tank that needs air bubbled in to keep anything alive, except no one’s running the bubbler. Rust needs oxygen, and so do the microbes that’d otherwise eat this stuff fastest, so both of them have a pretty slow time of it down there. The Park Service’s earlier robot surveys also found low oxygen inside the ship.<\/p>\n The study itself is a bit more careful than the quote. A team headed by University of Houston and WHOI researchers published it in Marine Pollution Bulletin, using samples the Park Service collected in 2016 and 2018. I could only read WHOI’s summary of the paper, which says the samples confirmed a heavy fuel made from California crude, and that fits what the Navy was burning back then.<\/p>\n Lighter compounds are slowly breaking down, though, and the chemistry changes depending on where the oil comes out. Lead author Jago\u0161 Radovi\u0107 says each leak ends up with its own fingerprint after working through the wreckage. Reddy also admits he doesn’t know exactly what the oil looked like on December 7, 1941, so his read on how little it’s changed is a well-informed estimate rather than a before-and-after test.<\/p>\n The oil also still carries a lot of PAHs, short for polycyclic aromatic hydrocarbons. That’s a family of compounds that stick around for a long time and can be toxic, although Reddy points out they aren’t all highly toxic.<\/p>\n Why do scientists care this much about one wreck? Thousands of World War II ships are sitting on the ocean floor with oil still in them, and Reddy puts the count at about 5,000. Most of them haven’t been sampled. With the Arizona, researchers at least have the backstory on the fuel: what it was, when it went in the water and what it’s been sitting in. Reddy says that’s already helping them make sense of leaks from the wrecks off Guadalcanal.<\/p>\n NIST is pretty blunt about this one. Its page says the oil can’t be completely removed without damaging large sections of the ship and intruding on what amounts to an underwater cemetery. It also says the Park Service and the Navy have been looking at nonintrusive ways to seal the fuel in for good. I can’t find anything on how far that’s gotten.<\/p>\n Reddy told KJZZ he wouldn’t try to take the oil out either. He called the ship a national shrine and said that outweighs what he sees as a relatively small amount of oil. He also said the Park Service talked to survivors and their families when the corrosion work got going in the 1980s and 1990s, and that they’ve supported the science.<\/p>\n I’d say that’s the right call. Cutting into tanks under a grave to fix a leak of a gallon or two a day seems like a pretty bad trade to me. British officials have landed on similar logic with the American Liberty ship sitting off the Thames with 1,400 tons of munitions<\/a>, though munitions are a very different kind of cargo.<\/p>\n Leaving the oil alone doesn’t mean no one’s touched the ship. In 1942, the Navy attached two concrete mooring platforms to the hull to help salvage her guns. They were never meant to stay, and they stayed for more than 80 years.<\/p>\n Then one of them partly gave way in October 2023, according to the Navy<\/a>. That’s a bigger deal than you’d think, since those platforms sat over parts of the ship that include fuel tanks. Cmdr. Matthew Englehart, the Pacific Fleet’s diving and salvage officer, said in a Navy release that their weight posed “a significant threat of collapsing through the decks.” The Historic Hawai\u2018i Foundation says the Navy feared that could set the remaining fuel loose.<\/p>\n So in May 2025, the Navy started placing containment buoys and anchors around the site, which is basically a floating fence for oil. On September 3, sailors and contractors started cutting up the platforms with a diamond wire saw and lifting the pieces out with a crane barge. It’s the same kind of saw a salvage crew used on that Liberty ship’s masts this fall. The job wrapped up on October 3, 2025.<\/p>\n The two platforms weighed an estimated 150-plus tons combined, and the crews took off more than 100 tons. They left small sections in place, because the Navy thinks pieces of the Arizona are stuck inside the concrete. The foundation says Navy divers logged 214 dives on the job, and it reports no impact on the ship.<\/p>\n I haven’t seen the Navy say whether taking that weight off changed the leak at all, and I wouldn’t expect a gallon or two a day to tell you much either way. Still, I find that job more reassuring than any of the estimates up above. Someone spotted a problem on a grave no one wants to disturb, the Navy spent about two years planning the fix and then took a month to do it.<\/p>\nSo how much oil is still in there?<\/h2>\n
A gallon or two a day, give or take<\/h2>\n
So why hasn’t the oil gone bad?<\/h2>\n
No one’s planning to pump it out<\/h2>\n
The Navy did take 100 tons of concrete off her, though<\/h2>\n
The ceremonies start a month from now<\/h2>\n