The most common and most likely answer to this crossword clue is the 9 letter word CATAMARAN
I've seen this crossword clue in The Times
C
A
T
A
M
A
R
A
N
More clues leading to the result CATAMARAN
- Boat made by Russian woman in prison
- Tom, a chap going round river on a boat
- Vessel, one crossing a river boundary
- Yacht clubs located in American islands
- Girl in tin boat
- Tin protects a river craft
- Bog engulfs a river boat
- Boat, vessel crossing a river
- A river passed around by vessel, multi-hulled craft
- American river crossed by container vessel
Buddy explains!

The straight part
We know that "Yacht" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case yacht = catamaran.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 CATAMARAN mean?
CATAMARAN noun- A twin-hulled ship or boat.
- A quarrelsome woman; a scold.
- A raft of three pieces of wood lashed together, the middle piece being longer than the others, and serving as a keel on which the rower squats while paddling.
- An old kind of fireship.