It is just over a year since the WWII destroyer USS Johnston was confirmed to be the world’s deepest shipwreck, found lying on the seabed 6,468.6 m (21,222 ft) below the surface. But after a short reign, its title has now been claimed by another.
Although located in the same vicinity as the Johnston – east of Samar Island in the Philippine Sea – the USS Samuel B. Roberts (“DE 413”) lies almost 400 m (1,300 ft) deeper at 6,865 m (22,523 ft), as discovered on 22 June 2022.
Initial reports suggested a maximum depth of 6,895 m (22,621 ft) but fine-tuning of the data recalibrated this by 30 m (100 ft) – nevertheless still setting new records for the deepest shipwreck found to date and the deepest shipwreck dive by a crewed vessel.
The Sammy B (as the US Navy ship is also known) lies almost as far below sea level as South America’s highest mountain, Aconcagua, rises above it. Or to put it another way, the vertical distance equates to a stack of 20 Eiffel Towers or eight Burj Khalifas (the world’s tallest building).
This vessel is almost double (i.e., 45%) the depth of that most famous of shipwrecks, the RMS Titanic, which lies some 3,800 m (12,470 ft) down in the Atlantic Ocean.
The destroyer escort ship, or frigate, formed part of the same task force as the Johnston (a destroyer and one of the vessels the Sammy B was tasked with defending). Both were victims of the high-casualty Battle off Samar on 25 October 1944.
This was one of the flashpoints of the wider Battle of Leyte Gulf fought between the US and Japanese navies at the tail-end of WWII. Some maritime historians consider this to have been the largest naval battle of all time.
With what appears to be apparently live ammunition still on board the USS Samuel B. Roberts to this day, for those that uncovered the wreck, there’s no question it went down fighting.
I had no idea if any of [the ammunition] could go off, so I had to be extremely careful around the wreck and its modest current not to bump into her. The last thing I wanted was to disturb some 78-year-old ammunition and test my submarine’s resistance to WWII-era munitions!” -Victor Vescovo
Spearheading the search for the Sammy B (and the Johnston before it) was multi-record holding American adventurer and retired US Navy officer Victor Vescovo. (Just a few weeks before discovering this shipwreck, Vescovo travelled into space, claiming another unprecedented milestone of exploration.)
His state-of-the-art deep-sea submersible, the DSV Limiting Factor, which Vescovo has used to visit the deepest points in Earth’s oceans, has proven invaluable in seeking out these long-lost vessels whose precise whereabouts have remained elusive for decades.
To track down the Sammy B, Vescovo teamed up with Eyos Expeditions and sonar specialist Jeremie Morizet. The Limiting Factor was augmented with cutting-edge sonar technology never before employed at such extreme depths.
Even with the advanced hardware, the team weren’t 100% they had found the Sammy B based on the sonar results until Vescovo and Morizet went to investigate. After two descents with no results, this was their third – and likely final – attempt.
"The problem with sonar is that it really can’t tell the difference between rock and metal – it only measures the reflection of sound waves regardless of what they bounce off," Vescovo explains.
"Therefore, where we chose to dive was far more based on the historical analysis of where she might be, and then when we were on the actual seafloor we used the submersible’s own sonar which is much more short-range but higher-resolution.
"With that sonar, which has an effective range of 100–150 m (330–490 ft), we conducted a search pattern and eventually came across a return that was unmistakably a wrecked ship."
The Sammy B’s exact coordinates have been kept classified to respect its status as a war grave; of its 224 crew members, 89 are estimated to have died when it sank.
After putting up a valiant fight against far superior numbers, the final blow for the Sammy B was dealt by the Japanese Imperial Navy’s flagship, the Yamato.
This gigantic gunship (along with its sister vessel, the Musashi) was the largest battleship ever built at 263 m (863 ft) long and fitted with 18-in-calibre (45.7-cm) guns.
The extent of the damage inflicted remains plain to see almost 80 years on, as Vescovo reveals.
"The Sammy B took an enormous amount of punishment during the battle, as evidenced by an extremely damaged aft section."
"One can see where one battleship round penetrated the aft deck and blew up, completely opening up the ship and causing her to sink. The two rudders were completely blown off – we never found them – and could not even see the stern as it was shredded.
"But the front of the ship was in quite good condition with most of her guns – some still loaded! – and her bridge intact."
She was more or less in one piece, even though the back third was [essentially] disconnected from the rest… So I would say she is actually in pretty great condition given what she went through, and how deep she fell in the water - Victor Vescovo
Incredibly, this latest chapter may not be the end of the deepest shipwreck odyssey for there are several other known contenders in this area that could push this record deeper still.
Where the Johnston and the Sammy B came to rest, both just shy of 7 km (4.3 mi) under the surface, the Philippine Trench – over which the Battle off Samar played out – plunges in excess of 10 km (6.2 mi) at its most profound point.
Vescovo tells GWR why the search is not over yet: "The US lost two other ships during the battle: the small aircraft carrier Gambier Bay and the destroyer Hoel.
"We conducted two dives looking for the Gambier Bay in waters even deeper than where we found the Johnston, hoping to find her, but we did not. We didn’t search for the Hoel because we have very little good data on where she went down.
"The Japanese also lost some ships in the area, and we are even less able to identify a good area to search for them.
"So yes, there could be even deeper wrecks than the Johnston and Sammy B, but they will be even more difficult to find. Not impossible, but more difficult. I look forward to trying."