AH-WR-1162

USS O-9

Submarine · United States · Lost 1941 · The Isles of Shoals & the New Hampshire Coast

A World War I-era Navy submarine, recommissioned to train new crews, failed to resurface off the Isles of Shoals during a 1941 deep-dive test, killing all 33 aboard.

Artistic recreation based on recorded historical documents. See the documented evidence.

Documented Likeness. Drawn from surviving builder's plans or clear photographs of this vessel. See the documented evidence.

The Vessel and Her Loss

USS O-9, a 1918-built O-class submarine, was recommissioned in April 1941 to help train submarine crews as war approached. On June 20, 1941, while conducting a deep-submergence test with two sister boats off the Isles of Shoals, O-9 submerged and never resurfaced. All 33 men aboard were lost. The Navy's salvage ship Falcon searched the area, but the aging hull, likely unable to withstand the pressure at the depth attempted, was not recovered. The wreck was located by sonar survey decades later, and NOAA led a documentation expedition in 2004.

Vessel

Built: 1918
Registry: SS-70
Builder: Fore River Shipbuilding Company
Yard: Quincy, Massachusetts
Material: Steel
Length: 172 ft
Beam: 18 ft
Tonnage: Not established
Propulsion: Diesel-electric, single screw configuration typical of O-class
Owners: United States Navy

Loss

Date: June 20, 1941
Cause: Mechanical failure
Location: About 15 miles southeast of Portsmouth, off the Isles of Shoals, New Hampshire
Water: Atlantic Ocean
Voyage: Portsmouth, New Hampshire
Cargo: Not established
Aboard: 33
Lives lost: 33
Master: Lt. Howard J. Abbott

The Wreck Today

Depth: 430 ft
Condition: Not established
Orientation: Not established
Discovered: 1997
Protection: Sunken military craft; protected as a U.S. Navy war grave under the Sunken Military Craft Act.

Position

Coordinates: Not established
Accuracy: Position not established
Nearest: Isles of Shoals, New Hampshire
Region: The Isles of Shoals & the New Hampshire Coast

General search area is documented by NOAA and Navy accounts, but a published exact position was not confirmed for this record.

Evidence

Overall confidence: Documented (80/100)

The precise cause of the casualty and an authoritative published wreck position were not confirmed in the sources reviewed.

Naval History and Heritage Command
Build history, recommissioning, date and circumstances of loss.
NOAA Ocean Explorer
Loss location, depth, sonar survey and discovery details.
U.S. Naval Institute, Naval History Magazine
Narrative detail on the loss and crew.