Sometimes, when a sailor has completed his RN service, he transfers to the Coastguard service. I have an ancestor who did just that and one of his postings was to a Coastguard ship. I was able to obtain his service record through a researcher, but you need some facts to go on - dob, marriage, places, census info etc. This was some time ago so I'm not sure if she is still doing this, but it is worth a try. Contact me off list for details. Vicki