Article overview: Trace Navy, Coast Guard, and Merchant Marine ancestors with a guide to muster rolls, service files, ship logs, and archives holding their maritime records.
Researching Navy, Coast Guard, or Merchant Marine ancestors starts with two questions: when did they serve, and aboard which ship or station? Personnel files tell part of the story; muster rolls, logs, and other vessel records can add context. This guide explains the main record types and where to begin a search without assuming that one archive holds everything.
Understanding the Maritime Branches
The U.S. Navy and U.S. Coast Guard are military services; the Merchant Marine is a civilian maritime workforce. Their records follow different systems. Coast Guard research may also involve its predecessor agencies: the Revenue Cutter Service, Life-Saving Service, and Lighthouse Service. The Life-Saving Service became a separate organization in 1878, following an earlier reorganization in 1871. It merged with the Revenue Cutter Service in 1915 to form the modern Coast Guard; the Lighthouse Service joined in 1939.
Before You Begin: Gathering What You Know
Before you submit a single records request, gather everything your family already knows. The most useful starting information includes your ancestor's full legal name, approximate birth year and birthplace, the branch they served in, the approximate years of service or the war they served during, and any ship or station name the family remembers.
Even a partial ship name is worth noting. Gather discharge papers, photographs, letters, newspaper clippings, and any service or mariner identification number. A ship name on a photograph can be a clue, but compare it with dates and documents before identifying a person’s service. Make a timeline and label uncertain details so they do not become assumptions in later searches.
Researching US Navy Ancestors
For early Navy ancestors, muster rolls can establish service aboard a ship or at a station. The National Archives describes its historical muster rolls as quarterly lists, with related reports recording changes. Official enlisted service records begin in 1885, so earlier research often depends on muster rolls, pension files, and other records rather than a single personnel file. Deck logs describe a vessel’s operations; they do not necessarily name every crew member. Cruise books can provide photographs and a crew’s account of a deployment.
Use the National Archives and Navy personnel-record guides to identify the custodian for the service period and record type. Navy enlisted personnel records from 1885 and officer records from 1902 are important starting points for personnel-file research. The major losses in the 1973 National Personnel Records Center fire concerned Army and Air Force files; do not assume that a missing Navy record was destroyed in that fire.
Researching Coast Guard Ancestors
Coast Guard records are spread across National Archives facilities and Coast Guard offices. Search by service dates, predecessor agency, vessel, station, and district. Record Group 26 includes many Coast Guard and predecessor-agency records. Station logs, annual reports, personnel records, and rescue reports can each answer different questions.
Wreck and rescue reports may name the crews involved, while Lighthouse Service records can identify keepers and assignments. Do not use a single date cutoff for every Coast Guard record. For example, the National Archives holds muster rolls from 1833–1949, while muster rolls from 1950 onward remain with the Coast Guard. Personnel files and operational records have their own coverage and custodians.
The Coast Guard Historian’s Office provides historical context and research guides. Use it alongside the National Archives catalog, and confirm the relevant record series before submitting a request.
Researching Merchant Marine Ancestors
Merchant mariners worked aboard civilian commercial ships, including vessels carrying wartime supplies. Their records may include seamen’s protection certificates, crew lists, shipping articles, discharge books, and licensing files. Distinguish a civilian mariner from a Navy Armed Guard sailor assigned to the same merchant ship: their personnel records follow different research paths.
The National Archives Merchant Marine personnel guide identifies collections in Washington, DC, and St. Louis, including licensing and casualty records. It directs requests for personnel or service records of mariners discharged by the Coast Guard to the National Maritime Center. Use the Center’s current records-request instructions and any required proof of eligibility; do not assume that every merchant mariner has a military personnel file.
Key Archives and Online Resources for Maritime Research
Start with the archive’s guide to the specific collection, then check its dates, location, indexing, and access rules. A catalog description is useful even when the records have not been digitized. Record the collection identifier and the name or vessel you searched so an archivist can understand what you have already tried.
Search original images whenever possible rather than relying only on an online name index. Compare spelling variants, ages, service numbers, relatives, and dates. If your ancestor also crossed the ocean as a passenger, our ship passenger list genealogy guide explains that separate record trail.
Glossary of Maritime Genealogy Terms
Casualties List: Official records of military personnel who were killed, wounded, missing in action, or taken prisoner.
Continuous Discharge Book: A logbook carried by a Merchant Mariner containing a running record of their sea service, vessel assignments, and discharge dates. Convoy: A group of merchant ships traveling together across the ocean under naval escort for protection against enemy submarines and aircraft.
Cruise Book: An unofficial, yearbook-style publication created by a ship's crew at the end of a deployment, featuring portraits, candid photos, and a narrative of the voyage. DD 214: The standard Department of Defense certificate of release or discharge from active duty, implemented in 1950.
Deck Log: The official daily record of a ship’s operations, detailing its position, weather conditions, disciplinary actions, and significant events.
Draft Registration: Mandatory federal records of men eligible for military conscription, often listing a person's current maritime employer or ship assignment.
Fleet: A large, organized group of naval vessels under a single commander or operating in a specific geographic theater.
IDPF: Highly detailed administrative files concerning military personnel who died in service, often detailing the circumstances of death and burial.
Keeper: The official title for the person in charge of managing a lighthouse or commanding a Life Saving Service station.
Line Officer: A naval officer trained to command warships and lead combat operations, as opposed to a staff officer like a doctor, chaplain, or engineer.
Muster Roll: A formal, official list of personnel assigned to a ship or station on a specific date, used for accounting and payroll purposes.
NAVPERS: A designation used on Navy personnel forms and publications; note the full form number when identifying a document.
OMPF: The primary administrative record of an individual's military service, encompassing enlistment contracts, duty stations, awards, and discharge papers.
Pension File: Extensive files generated from financial claims submitted by veterans or their dependents, often containing rich genealogical data, marriage certificates, and medical histories.
Rank: An officer’s grade or level of authority; record the exact wording used in the source.
Rating: The occupational specialty or job title of an enlisted sailor in the Navy or Coast Guard.
Revenue Cutter: A lightly armed, fast customs enforcement vessel operated by the Revenue Cutter Service to collect tariffs and suppress piracy.
Seaman's Protection Certificate: A document issued to American sailors in the late 18th and 19th centuries to prove their citizenship and help protect them against impressment by foreign navies.
Ship's Articles: The official contract signed by a Merchant Marine crew outlining the terms, wages, and destination of a specific voyage.
Station Log: The daily operational diary kept by the keeper of a Life Saving Service or Coast Guard station, noting patrols, weather, and rescues.
Surfman: A highly trained member of a Life Saving Service crew whose primary duty was to perform rescues in heavy, dangerous surf conditions.
Warrant Officer: An officer appointed for specialized technical expertise; titles and appointment practices vary by service and period.
Wreck Report: A detailed official account of a maritime disaster, grounding, or rescue operation submitted by the Life Saving Service.
Z Number: The unique identification number issued to Merchant Mariners by the Coast Guard, essential for tracking their mid-20th-century service records.