The most common and most likely answer to this crossword clue is the 6 letter word CREWED
I've seen this crossword clue in Financial Times
C
R
E
W
E
D
More clues leading to the result CREWED
- Having sailors using filthy language audibly maybe?
- Worked on a boat unprepared to be heard
- Was a staff member on boat sounding rough?
- Pronounced ‘basic’, as ship will be before sailing
- Having company with set of principles carrying little weight
- Served on board, sounding vulgar
- Operated craft with a hundred that had married again
- Had workers with divided beliefs
- Put men on board lacking refinement, we hear
- Were sailors coarse in speech?
Buddy explains!

The straight part
We know that "Was a staff member on boat" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case was a staff member on boat = crewed.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CREWED mean?
CREWED adjective- Having a crew; manned; piloted.