I have to agree with all the adverse comments. As I posted on the FifteenSquared site, I originally had the clue as:
"Conclude port swallowed is of a lower standard", but when typing out from my scribbled notes thought that I'd make it shorter by replacing "Conclude" with a shorter word. Picking up my nearest thesaurus I saw "Imply". Doh!
I now imagine my grammar school English teacher turning in his grave. Although I joined the RN at age 15 as a Boy Seaman, I have no excuse for forgetting what he stressed. On the site I gave myself 5 marks out of 10 and "Could do better".