The most common and most likely answer to this crossword clue is the 7 letter word DOCKING
I've seen this crossword clue in The Guardian
D
O
C
K
I
N
G
More clues leading to the result DOCKING
Buddy explains!

The straight part
We know that "Crafty manoeuvre/which a clipper might perform" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case crafty manoeuvre/which a clipper might perform = docking.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 DOCKING mean?
DOCKING verb- To cut off a section of an animal's tail, to practise a caudectomy.
- To reduce (wages); to deduct from.
- To cut off, bar, or destroy.
- To land at a harbour.
- To join two moving items.
- To drag a user interface element (such as a toolbar) to a position on screen where it snaps into place.
- To place (an electronic device) in its dock.
- To pierce with holes, as pricking pastry or dough with a fork to prevent excessive rising in the oven.
- The process of cutting off or trimming the tail or ears of an animal.
- The securing of a vessel to the quayside with cables
- The process of connecting one spacecraft to another.
- The sex act involving two men co-joined by their penises, with overlapping foreskins, coupling them together by their penises.
- A method which predicts the preferred orientation of one molecule to a second when bound to each other to form a stable complex.