// Officer Designator · O-1 to O-10 · NATO OF-1 to OF-9

SUBMARINE OFFICER (1120)

The nuclear-trained URL community that operates the Silent Service.

Insignia

Designator

1120

Abbreviation

SUB

Community

Unrestricted Line

Paygrade Range

O-1 to O-10

NATO Range

OF-1 to OF-9

OVERVIEW

The 1120 Submarine Officer designator identifies Unrestricted Line officers in the U.S. Navy who serve aboard nuclear-powered fast-attack (SSN), ballistic-missile (SSBN), and guided-missile (SSGN) submarines. Submarine Officers are nuclear-trained and qualify both as engineers of a naval reactor plant and as warfare officers of the boat. The community is small, intensely selective, and the operational engine behind the U.S. Navy's strategic deterrent and undersea warfare missions.

A new Ensign with the 1120 designator spends roughly 15 months in the rigorous Naval Nuclear Power and Submarine Officer Basic Course pipeline before reporting to a fleet boat. The community is famous for its 18-month "qualification in submarines" — culminating in the gold "Dolphins" pin, the second-oldest warfare device in the Navy.

RESPONSIBILITIES

Operate the propulsion plant of a nuclear-powered submarine as a qualified engineer
Stand watch as Officer of the Deck and Engineering Officer of the Watch (EOOW)
Serve as a Division Officer leading enlisted Sailors in the engineering, weapons, or navigation/operations divisions
Progress to Department Head, Executive Officer, and Commanding Officer of an SSN, SSBN, or SSGN

HISTORY

The U.S. Navy submarine force was established in 1900 with the commissioning of USS Holland (SS-1). The Submarine Warfare Officer "Dolphins" insignia was authorized in 1924, making it one of the oldest warfare pins in the Navy. The community was transformed in 1955 when USS Nautilus (SSN-571) became the world's first nuclear-powered vessel; from that point forward, every U.S. submarine officer has been required to complete the Naval Nuclear Propulsion Training pipeline founded by Admiral Hyman G. Rickover.

Today the submarine community fields the Virginia-class SSN, the Ohio-class SSBN/SSGN, and the in-development Columbia-class SSBN. Submarine Officers split assignments roughly between the Pacific (Pearl Harbor, Bangor, Guam) and the Atlantic (Groton, Kings Bay, Norfolk).

COMMISSIONING SOURCES

USNA
NROTC
OCS
STA-21

TRAINING PIPELINE

1. Naval Nuclear Power School (NPS)~6 months
Charleston, SC
Graduate-level nuclear-engineering academic training.
2. Nuclear Power Training Unit (Prototype)~6 months
Charleston, SC or Ballston Spa, NY
Hands-on operation of a working naval reactor plant.
3. Submarine Officer Basic Course (SOBC)~3 months
Groton, CT
Submarine tactics, ship-control, weapons, and damage control.

TYPICAL CAREER PATH

O-1
Nuclear Power School + Prototype
Six months of academic nuclear-engineering training followed by six months of hands-on prototype reactor operation.
O-1/O-2
Submarine Officer Basic Course (SOBC)
Three months of submarine tactics, weapons, and ship-handling at Naval Submarine School in Groton, CT.
O-2/O-3
Junior Officer Sea Tour
Earn "qualification in submarines" — the gold Dolphins — and serve as Division Officer, EOOW, and OOD on a fleet submarine.
O-4
Department Head
Engineer, Weapons, or Navigator/Operations Department Head aboard another fleet boat.
O-5
Commanding Officer
Command of an SSN, SSBN, or SSGN submarine.

RELATED DESIGNATORS

RELATED BASES

How to address

Same as the underlying officer rank — e.g., "Lieutenant Smith" — with community addressed as "Submarine Officer" or "Sub" in writing.

Prerequisites

Strong technical background — engineering, math, or physical science degree preferred
Successful completion of the Naval Reactors interview in Washington, D.C.
Pass Naval Nuclear Power School and Prototype training
Pass the Submarine Officer Basic Course at Naval Submarine School, Groton, CT

Common assignments

Division Officer aboard a Virginia-class SSN out of Groton or Pearl Harbor
Department Head aboard an Ohio-class SSBN out of Kings Bay or Bangor
Engineer Officer or Executive Officer of a fast-attack submarine
Squadron, group, or Naval Reactors staff billet

FREQUENTLY ASKED QUESTIONS

The 1120 designator identifies an Unrestricted Line officer in the Submarine Warfare community — a nuclear-trained officer qualified to operate U.S. Navy submarines.

A typical Submarine Officer spends roughly 15 months in initial training — six months at Naval Nuclear Power School, six months at a prototype reactor, and three months at Submarine Officer Basic Course — before reporting to a fleet submarine.

All prospective submarine officers must interview personally with the Director of Naval Reactors in Washington, D.C. The interview is famously rigorous and is the gateway to the entire submarine community.

SOURCES

Last updated 2026-05-02

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