We're coming up on the six-month point following the solo deep-dive of Deepsea Challenger. James Cameron is immersed in movies again and his green submarine has thoroughly vanished from the newsfeeds, presumably to resurface as a 3D movie in late 2012, accompanied by an article about the Mariana Trench in National Geographic. But the adventure must have been fun while it lasted. Along the way I posted info-graphics like this:
Skeptics wondered if anything was behind the big splash in late March other than Cameron's desire to set a solo record and facilitate certain movies, but oceanographic experts were part of the expedition and the Deepsea Challenge project should produce some worthwhile science. I predict most of the value will come from work by the two unmanned landers rather than the manned sub, because the landers could stay down for long periods.
This sidebar question came up among the many articles that dutifully relayed Cameron news that month: What's the deepest shipwreck? Sir Richard Branson said in an interview with the Christian Science Monitor that the oceans has thousands of unexplored wrecks, including galleons: "Magnificent exploration potential," said he.
So that made me wonder what the deepest wreck might be that's still ripe for discovery. I checked with salvage sources and while the question can't be answered with any certainty given the early state of hadal-zone exploration, it's possible to come with a short list of candidates.
Here's my nominee: a Japanese submarine sunk during a battle offshore of Samar Island in October 1944, which was a center of action during the Battle of Leyte Gulf.
US Navy records indicate that the destroyer escort Richard M. Rowell sunk a Japanese submarine with depth charges on October 24 at 09 d. 45'N., 126 d. 45'E. For some years war historians reckoned this casualty as I-362, but according to more recent postings on Wrecksite.eu it was I-54, which looked like this:
The sub went down over the Philippine Trench:
That's just west of the Emden Deep's lowest point. This from NOAA's multibeam-sonar bathymetry page:
Other warships hit during the Battle Off Samar could have glided into places as deep that day, but from the battle reports available, I'd vote for I-54 as one of the deepest shipwrecks anywhere, coming to rest at 25,000 to 30,000 feet.
So if Sir R.B. still has lots of money to spend, and if he still wants to go face to face with a hulk never ravaged by treasure-hunters, the Emden Deep would be a good place for Virgin Oceanic to visit.