The service of merchant seamen in war should not be overlooked: they suffered hardship under enemy fire as much as the men of the Royal Navy.
Sea officers were required to have certificates of service or competency from 1845 onwards.
In addition to these records, those related to ordinary seamen should also be consulted - see below.
Service registers for ordinary seamen were kept between 1835 and 1857.
No service registers were maintained between 1858 and 1912. But following this gap of 56 years, the keeping of service registers began again in 1913; those up to 1972 are at The National Archives.
Many seamen saw service, especially during the First World War, in the Royal Naval Reserve. Records of this are available at The National Archives.