Military Service

Canterbury Record Office and Dover Library
It would be useful to visit Canterbury Record Office to gain further information about Ernest Highams prior to his military career.   Information held there includes Parish records for the whole of Kent, so his Baptism record should be found there.
In addition a visit to Dover library would be beneficial to search for information about the family business of butchers.

The National Archives, Kew
A visit to the National Archives in Kew may hold additional records to his service records already provided.
Although he was not married, his mother may have been entitled to a pension on his death.   This should be searched in references PIN 26 and PIN 82.  
In addition, log books of the ships he served on could also be searched to obtain detail of where his ships sailed to in the times he was aboard and also the station records.   These may be found in ADM 53 and the station records under a number of references between ADM 121 and ADM 179.
Operational records for the Royal Navy in WW1 can also be searched for additional information such as papers and letters – ADM 1.
Finally, Navy medal records can be found in ADM 171.

Royal Naval Museum, Portsmouth
The museum holds information of the Navy in general and individual people.   There is also a research facility at the museum.   I would hope to find a record of Highams on a copy of a Naval Roll or Muster Roll.

National Maritime Museum, Greenwich
There is a research facility at the Museum.   If I was to visit I would search for further information on the vessels such as logs and navigation records as well as personal papers if available.   This information would complement information found at The National Archives.

Other record sources which you may be able to find additional information about Fred Wilkinson and his military service...