TNA RN Service records This from the National Archives website - it appears that they have extended the coverage of RN service records:
The records of seamen who joined the Royal Navy between 1853 and 1923 can now be searched and downloaded from Documents Online, The National Archives' digital records service.
While many of the records from the Registers of Seamen's Services (ADM 188) and the Continuous Service engagement books (ADM 139) have previously been digitised, we have only recently completed the collection by releasing the final batch of files (ADM 139/221 - 1027) online. This means that over 680,000 records on Royal Naval seaman are now available to search and download.
From the late 1820's the Admiralty published quarterly officers lists which were printed yearly in small books called "Navy Lists". Locations of officers, and ships, world wide were printed in these little volumes.Included were lists of Officers employed in the service of the coastguard in England, Ireland, Scotland and Wales....