O-9 SS-70

A beautiful 1.75-inch hand-painted brass coin honoring the 33 men lost on the USS O-9 SS-70 June 20, 1941.

The following excerpt is from "Submarine History Archive:

On 27 July 1918, the United States commissioned USS O-9 (SS-70). Her crew stretched their new boat's legs in the waters off the United States eastern coast, protecting the shores from marauding U-boats. On 2 November 1918, she left Newport, Rhode Island, for Europe, where she was scheduled to undertake her first wartime patrol. Fortunately for the world as a whole, but unfortunately for O-9's eager crew, hostilities ceased before the boat arrived in Britain.
O-9 returned to the U.S., where she became a training vessel at Submarine School in New London, CT. She was decommissioned and mothballed in 1931, but as it became clear towards the end of the decade that another war was at hand, she, along with eight other O-class boats, was recommissioned and put to work training prospective submariners. All the boats needed some TLC, which was understandable given their age, but O-9 was in particularly bad shape. Mechanical problems persisted even after she returned to service.
On the morning of 20 June 1941, three submarines; O-6, O-9, and O-10 left New London, bound for the submarine test-depth diving area east of the Isles of Shoals, which lie about six miles off the coast of New Hampshire and Maine; the area where the subs were to submerge was 15 miles out from Portsmouth. O-6 dove first. O-10 followed. At 0837, O-9 sank beneath the waves. Two hours later, she still had not returned to the surface. O-6 and O-10, accompanied by another submarine, USS TRITON (SS-201), and the submarine rescue ship USS FALCON (AM-28), began a search for the missing boat. All they recovered was a few pieces of debris with markings that identified them as coming from O-9.
Over the course of the next two days, divers descended to the bottom of the frigid Atlantic, nearly 450 feet below the ocean's surface, in search of the wreck. Although they set records for endurance and depth, they found nothing. On the 22nd the operation was canceled, deemed to be too risky. The boat was declared lost, along with her 34 officers and crew, as of the 20th. It was presumed that O-9 had, for some reason, passed below her crush depth of 212 feet and imploded.
For more than 56 years, the exact location of the wreck of O-9 was a mystery. But in 1997, Glen Reem, retired Navy Captain, scuba diver, and nautical researcher, teamed up with two side-scan sonar experts from Klein Associates and went looking for her. On 20 September they found O-9, resting on her side on the ocean floor. In 2004, a team sponsored by NOAA photographed the wreck, looking for clues as to what had sent the boat to the bottom. Her conning tower, although bedecked with lost fishing gear, was intact, as was her bow. None of the escape hatches was open. "Aft of the conning tower the vessel had collapsed," said Rick Yorczyk, the project manager, "but it did not appear to be the result of an explosion or collision. There is some closure in the sense that the lost crewmembers have been found, but in the end, why the submarine sank remains a mystery."
Regardless of how she got there, O-9 and her crew remain where they came to rest more than seventy years ago. The exact location of the boat has not been revealed to the public, and the area has been designated an official burial ground by the Navy.