You have to love the humour that lies behind a sailor’s terminology. Firstly, there is a set of ‘standard’ nicknames that go with surnames – Dusty Miller, Rusty Hinge and so on. Then there are nicknames that reflect observations – I had one bloke work for me whose nickname was ‘Dog’s breath’ and another called ‘Yapper’ – you can guess.
Typical of this terminology is the Dockyard Oyster. This is a heap of phlegm on the ground that resulted from someone hawking it up. It’s nastily apposite – it looks a bit like an oyster, and you can imagine that, like an oyster it’d be salty. Urgh.
If you search the web for Jackspeak, you’ll find a fair few links. I think that ‘Jackspeak’ was first a book written by a Royal Marine surgeon and was a sort of dictionary guide to British Naval slang & usage. The search yields places to buy the book, and a few web pages that purport to do the something similar.