How do I trace a servicemans history from his service number of JX131312?

Question:

How do I trace a servicemans history from his service number of JX131312?

His name was Sidney Spencer and he served on the HMS Dunedin WW2 on which his was listed as MIA when she went down.
His parental family are all from Yorkshire but his wife and daughter lived (daughter still does) in Portsmouth. There are no documents relating to Sidney or photographs as everything was destroyed in the bombings.
Any information on him or his parental family is eagerly desired.

Best Answer - Chosen by Asker: The service number is a start - but you will need to show it to government / naval officials - people with access to the information.

You will need to consult navy / government records first - the navy official records should have what had happened to him.

Maybe also check enlistment records - see when and where enlisted, what happened after they enlisted - where they trained, and any information where they were transferred to duty.

Next you could look on the internet for any websites where ex-naval sailors / staff discuss or organise meetings - and if the HMS Dunedin had any survivors - and if they still meet regularly somewhere.

Look for Returned Services meetings of naval staff - make inquiries about who can help you to look into it.

If you do find someone that might know someone, ask permission to speak to them - privately. Provide your credentials of who u are and your concerns what your looking for and see if survivors know of him - or remember him.

Good luck in your quest.