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Marine Corps MOS · Combat & Infantry

0321 Reconnaissance Marine

Current service use not established

This code is listed in the directory. Inclusion alone does not confirm current service use.

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Overview

A Reconnaissance Marine conducts multi-domain reconnaissance and surveillance, long-range patrols, scouting, and intelligence collection in support of commanders. The Marine also performs combat swimming, small boat operations, demolitions, supporting arms observation, long-range communications, parachuting, and combatant diving.

Minimum clearance: Secret

Minimum ASVAB: CL 105 or GT 105

ASVAB policy: Not policy-reviewed · coverage unknown · as of 2026-10-19

Program scope has not been reviewed.

Policy applicability and coverage of the program's score routes have not been reviewed. Shown-route arithmetic is not an eligibility decision.

Source: navmc-1200-1l-fy26 (source date 2025-03). Policy applicability has not been established.

See if you would hit this score: free ASVAB practice test

Core Skills

  • Combat swimming and small boat operations
  • Combatant diving and underwater access
  • Threat weapons and equipment identification
  • Long-range communications for intelligence collection

Civilian Career Paths

Career associations are editorial assessments of the cited evidence, not an official crosswalk unless the evidence explicitly says so. O*NET supplies civilian occupation information, not proof of a military match. Related experience does not confer civilian qualifications. Tasks and tools below describe civilian work, not military training.

Motorboat Operators

Military small boat operations provide directly relevant experience for operating civilian motorboats.

How to prepare: For work requiring a USCG endorsement, assemble an official sea-service transcript or assignment history with vessel characteristics, underway time and assigned duties for Coast Guard evaluation against the endorsement sought. Military service can receive sea-service credit, but a DD-214 alone is not acceptable evidence.

What the civilian work involves
  • Operate engine throttles and steering mechanisms to guide boats on desired courses.
  • Secure boats to docks with mooring lines, and cast off lines to enable departure.
  • Maintain desired courses, using compasses or electronic navigational aids.
Civilian tools and software (examples)
  • Global positioning system GPS software
  • Radar software
  • Echo sounder software

Commercial Divers

Combatant diving training provides an underwater-work foundation for commercial diving assignments.

How to prepare: Ask a commercial diving employer to assess existing qualifications, military training records and dive logs against the intended tasks and diving mode before choosing gap training. Where ADCI certification is used, its Entry Level classification requires 625 documented hours of specified formal instruction or a recognized equivalent, so seek an equivalency assessment first.

What the civilian work involves
  • Check and maintain diving equipment, such as helmets, masks, air tanks, harnesses, or gauges.
  • Communicate with workers on the surface while underwater, using signal lines or telephones.
  • Obtain information about diving tasks and environmental conditions.
Civilian tools and software (examples)
  • Diving logbook software

DIA Analysis Officer

Multi-domain intelligence collection and threat weapons identification provide relevant military context for DIA's Military Capabilities analysis specialty.

How to prepare: Prepare an unclassified analytical writing sample on foreign military capabilities to practice for DIA's writing test and interview. DIA welcomes applicants from any educational track, but requires U.S. citizenship, a granted security clearance and completion of its background and employment screening, including any required medical or polygraph examinations and drug screening.

Training & Development

Choose credentials for your target role. COOL funding markers describe program listings, not a guarantee of eligibility or funding.

Getting Started

  • USCG Merchant Mariner Credential

    Support Motorboat Operators positions requiring a Coast Guard endorsement appropriate to the vessel and service.

    Eligibility and preparation: Meet the requirements of each endorsement sought, including applicable sea service and medical, vision, hearing or physical standards; hold or have applied for a TWIC; and provide a qualifying drug test or exemption. The MMC authorizes service only within its endorsed capacities.

    For: Motorboat Operators

Notes & Sources

  • For commercial diving covered by OSHA, assigned tasks must match documented experience or training in the relevant equipment, diving mode and emergency procedures. CPR and first aid training are required, with diving physics and physiology training for those exposed to or controlling hyperbaric exposure.
  • OSHA permits limited additional diving tasks during training only under direct supervision of an experienced dive team member, and prohibits hyperbaric exposure during a known temporary condition likely to impair safety.
Evidence for this guidance (9 documents)
  1. NAVMC 1200.1L (FY26, in force): MOS 0321

    [1] MOS 0321 section "a. Summary"; cached text line 27490; NAVMC 1200.1L signed 2025-03-07, in force until 2026-10-01

    Supports: Combat swimming and small boat operations, Combatant diving and underwater access, Threat weapons and equipment identification, Long-range communications for intelligence collection, Motorboat Operators (O*NET 53-5022.00), Commercial Divers (O*NET 49-9092.00), DIA Analysis Officer

  2. O*NET: Motorboat Operators

    [2] O*NET 30.3 occupational data

    Supports: Motorboat Operators (O*NET 53-5022.00)

  3. USCG: 46 CFR 10.232 military sea-service evidence and credit

    [3] Paragraphs (a) and (d)(1), official eCFR snapshot September 21, 2026; retrieved September 24

    Supports: Motorboat Operators (O*NET 53-5022.00)

  4. eCFR: 46 CFR part 10 - Merchant Mariner Credential issuance requirements

    [4] 46 CFR 10.201, 10.209 and 10.225; official eCFR XML API as of 22 September 2026

    Supports: Motorboat Operators (O*NET 53-5022.00), USCG Merchant Mariner Credential

  5. O*NET: Commercial Divers

    [5] O*NET 30.3 occupational data

    Supports: Commercial Divers (O*NET 49-9092.00)

  6. OSHA 29 CFR 1910.410: Qualifications of dive team

    [6] Commercial Diving Operations, paragraphs (a) and (b). Verified 2026-09-24.

    Supports: Commercial Divers (O*NET 49-9092.00)

  7. ADCI: Commercial diver classification requirements

    [7] Entry Level and Air Diver card classifications. ADCI framework, not a universal government license. Verified 2026-09-24.

    Supports: Commercial Divers (O*NET 49-9092.00)

  8. Defense Intelligence Agency: Analysis Career Field

    [8] Career Specifics, Military Capabilities, Applying to Be an Analyst; public page retrieved through Jina Reader 2026-09-23

    Supports: DIA Analysis Officer

  9. Defense Intelligence Agency: Hiring Process

    [9] Opening hiring overview and Employment Criteria, Initial Employment; public page retrieved through Jina Reader 2026-09-23

    Supports: DIA Analysis Officer

Defense contractor jobs for 0321

Descriptions may be summarized for clarity. Verify all information with your branch career counselor or official military documentation before making career decisions.

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