Why merchant seamen are among the best-documented ancestors

If your ancestor went to sea in the Merchant Navy, you are in luck. From the mid-nineteenth century onwards, the Board of Trade required masters to keep crew agreements and official log books, and to deposit copies with the Registrar General of Shipping and Seamen. The result is a paper trail that can name a man's age, birthplace, rating and the ship he sailed on — detail that is often impossible to find for other working people of the same period.

A crew list will typically give a seaman's name, age, place of birth, rating and the ship on which he had previously served. Cross-referencing those entries lets you follow a man from ship to ship, and from port to port, sometimes across decades. The log book adds colour: weather, desertions, injuries, disciplinary hearings, births and deaths at sea.

Do bear in mind that the Royal Navy and the Merchant Navy kept completely separate records, and that many men served in both. If your family story says "he was in the navy", it is worth checking both possibilities before you assume anything.

Start with what the family already knows

Before you order anything, gather the scraps you already have. Photographs in uniform, discharge books, certificates of competency, letters posted from foreign ports, obituaries that mention a ship, even a tattoo described on a document — all of it narrows the search.

Then write down the three essentials: a reasonably confident full name, an approximate year of birth, and a place of birth. Merchant Navy records are usually searched by name and date of birth, and a common name without a birth year is a recipe for frustration. Ask older relatives about nicknames and middle names too; men often shipped under a slightly different version of their name.

Crew lists and agreements: the core records

The crew agreement was signed at the start of a voyage and covers everyone aboard, from master to cabin boy. Surviving agreements from 1857 onwards are held in large series at The National Archives at Kew, with coverage becoming much fuller after 1861. A substantial portion of the 1861–1913 agreements is held in a sister collection in Canada, so if a voyage you expect cannot be found in Britain, it is worth checking whether it survives elsewhere.

Log books, kept by the master, sometimes survive alongside the agreements. They are less comprehensive than the crew lists for names, but they can be wonderfully evocative.

To find the right ship, you need its official number or its port of registry. These appear in the annual registers of merchant shipping and in the Mercantile Navy List, which together act as a index to the fleet. Once you have an official number, you can track a vessel through changes of owner and name.

Register tickets and continuous records

From 1913, seamen were issued with a register ticket — a small identity document carrying a photograph, a signature and a personal description. The associated registers, often called "CR10" cards, are searchable by name and cover men serving up to the early 1970s. They are the single most useful starting point for a twentieth-century seaman, because they list the ships he joined and the dates he joined them.

Later records, including the "fifth register" of seamen covering roughly 1941 to 1972 and the seamen's pouches, add further detail: next of kin, home address, date and place of birth, and sometimes a photograph. These are held at The National Archives in series beginning BT, and many of the twentieth-century indexes can be searched online before you visit.

Medals, deaths at sea and wartime service

Merchant seamen were eligible for campaign medals in both world wars, and the medal rolls are indexed. First World War awards include the Mercantile Marine Medal, and Second World War service is documented in the seamen's registers and in the records of the Registrar General of Shipping and Seamen.

For men who died at sea, there is a separate and very useful set of records:

• The marine register of births, marriages and deaths at sea, held with the general register records.
• Commonwealth war graves records, which often give a ship, a date and a next of kin.
• Newspaper reports from the ship's home port, which frequently named local men lost.

Deaths at sea were also reported in the ship's log and in the crew agreement, so a gap in the record is not always an absence of evidence.

Practical tips for a successful search

• Work back from the ship, not the man. If you know a vessel's name, find her official number first, then look for crew lists.
• Search every spelling. Names were written down by clerks in a hurry, from accents they did not recognise.
• Check both services. A man may appear in Royal Navy records for one period and Merchant Navy records for another.
• Expect gaps. Not every voyage survives, and coverage varies by year and by port.
• Read around the trade. Knowing whether your ancestor was a fireman in the coal trade or a steward on a liner tells you which ports and ships to search.
• Keep a research log. Record every reference you check, successful or not, so you never repeat a fruitless search.

Merchant Navy research rewards patience and method. Start with a name, a date and a place, follow the ships rather than the stories, and you will often find a man who left a surprisingly complete account of his working life on the record.