Maritime Archive and Library
From 1845 men intending to become masters or mates of foreign-going British merchant ships had to take voluntary examinations of competency. This system was made compulsory by the Marine Act of 1850 and the Merchant Shipping Act of 1854 and extended to engineers in 1862.
Certificates of Service were issued to long-serving, experienced seamen, but those without sufficient service, or wishing to rise in rank, were granted Certificates of Competency on passing formal examinations. The National Archives has indexes of certificates granted, and the original certificates issued before 1900 are kept at the National Maritime Museum. The Maritime Archives and Library have some examples of certificates in shipping company archives or the collections of individuals.