The most common and most likely answer to this crossword clue is the 10 letter word PADDLEBOAT
I've seen this crossword clue in The Guardian
P
A
D
D
L
E
B
O
A
T
More clues leading to the result PADDLEBOAT
Buddy explains!

The straight part
We know that "a crafty thing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a crafty thing = paddleboat.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 PADDLEBOAT mean?
PADDLEBOAT noun- A boat propelled by a paddle wheel