Ship's latrine OK after turbulence (3,6)

I believe the answer is:

oil tanker

I'm a little stuck... Click here to teach me more about this clue!

'ship's' is the definition.
(oil tanker is a kind of ship)

'latrine ok after turbulence' is the wordplay.
'latrine ok' anagrams to 'OIL TANKER'.
But, I am unsure how this is indicated.

Can you help me to learn more?

(Other definitions for oil tanker that I've seen before include "Ship carrying fuel" , "Fuel transporter" , "Ship carrying "black gold"" , "boat" , "craft" .)

I've seen this clue in The Times.

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