The most common and most likely answer to this crossword clue is the 10 letter word ALONGSHORE
I've seen this crossword clue in The Times
A
L
O
N
G
S
H
O
R
E
Buddy explains!
The straight part
We know that "somewhere on the coast" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case somewhere on the coast = alongshore.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 ALONGSHORE mean?
ALONGSHORE adjective- At or along a shore or coast.
- At or along a shore or coast.