Deep-ocean explorer Victor Vescovo and his team have located and dived the world’s deepest known shipwreck – the USS Samuel B Roberts (DE-413), found resting at a depth of 6.9km.
Known to her crew as the Sammy B, the warship’s role in World War Two’s Battle of Leyte Gulf in the Philippines earned her the accolade “the destroyer escort that fought like a battleship”.
Vescovo carried out the dive on 22 June in his two-person Triton submersible Limiting Factor alongside French sonar specialist Jeremie Morizet of Deep Ocean Research. They were able to explore the wreck from bow to stern, finding that it had broken into two sections that lay about 10m apart.
Last year Vescovo had descended to explore the USS Johnston, which at that time was the world’s deepest wreck dive at 6.47km, as reported on Divernet. Lying 426m deeper, the Sammy B sank in October 1944 during the Battle of Samar, the final engagement of the Battle of Leyte Gulf, which has been described as the biggest naval battle of WW2 and arguably of all time.
Captained by Lt-Cdr Robert W Copeland, the 93m Butler-class Sammy B was significantly outgunned by the powerful Japanese fleet. She carried fewer than half the guns, a third of the torpedoes and was slower than a Fletcher-class destroyer such as the Johnston, but according to witnesses she took on three Japanese battleships including the largest battleship ever built, the Yamato. Her guns also caused significant damage to two Japanese heavy cruisers, the Chokai and Chikuma.
Having used almost all her ammunition, the Sammy B was hit by Japanese fire including a critical strike from one of the battleships, and eventually sank. Eighty-nine of the 224 crew were killed, but Lt-Cdr Copeland survived and was later awarded the Navy Cross.
The Sammy B and the other destroyer escorts had damaged and delayed the Japanese fleet to the point that its commander Admiral Kurita was forced to retreat.
Historical records of the wreck’s position proved to have been inaccurate, but it was located through archival research led by Lt-Cdr Parks Stephenson, an affiliate of Vescovo’s company Caladan Oceanic who had also led the research that revealed the USS Johnston.
A Kongsberg EM-124 deep-ocean sonar was used for bathymetry and backscatter analysis from the expedition ship, but Vescovo equipped Limiting Factor with what is described as a first-of-its-kind sidescan sonar system, built by Deep Ocean Search to operate at full-ocean depth (11km, the usual limit being 6km). A shorter-range Kongsberg Mesotech 1000 high-frequency sonar was also used.
Caladan Oceanic and the organising EYOS Expeditions team carried out six dives over eight days from 17-24 June, searching not only for the Sammy B but also the aircraft-carrier Gambier Bay (CVE-73), though two dedicated dives at more than 7km failed to reveal the latter.
On the second day Australian pilot Tim Macdonald of Caladan Oceanic and Morizet located debris including a three-tube torpedo launcher – and were aware that the Sammy B had been the only one of the sunken warships to be armed in that way.
The broken body of the wreck was then located on the slope, with video footage capturing details including the fallen mast and the aft gun-turret where, as Vescovo describes it, “the brave and mortally wounded Gunner’s Mate Paul H Carr died trying to place a final round into the broken breech”.
“It was an extraordinary honour to locate this incredibly famous ship, and by doing so have the chance to retell her story of heroism and duty to those who may not know of the ship and her crew’s sacrifice,” said Vescovo. “I always remain in awe of the extraordinary bravery of those who fought in this battle against truly overwhelming odds – and won.”
“As ever, there’s been an incredible and dedicated effort by the whole team – the ship’s crew, sub team, historians and other specialists,” added expedition leader Kelvin Murray, director of expedition operations & undersea projects for EYOS Expeditions.
“Using a combination of detective work and innovative technology, everyone has pulled together to reveal the final resting place of this tenacious ship. It’s been a challenging, thrilling and poignant expedition, one that recognises the ships and sailors from all nations who fought so hard during this battle.”
All data related to the dive, including sonar maps, video and photographs, will now be donated to the US Navy’s Heritage & History Command.
After successful trials including the Samuel B Roberts dives, in early July Caladan Oceanic intends to take the new Deep Ocean Search sidescan sonar all the way down to the deepest point on Earth, the Mariana Trench’s Challenger Deep, as part of a series of four dives mapping previously unvisited parts of the system.
Also on Divernet: World’s Deepest Diver Cracks Atacama Trench, First Humans Dive Into Emden Deep, Son Follows Father On Deepest Dive, Vescovo Becomes Deepest Diver – By 16m