The most common and most likely answer to this crossword clue is the 8 letter word HORNPIPE
I've seen this crossword clue in The Times
H
O
R
N
P
I
P
E
More clues leading to the result HORNPIPE
- Spooner’s blue material advertising dance
- Hope to engage sailors with very good dance at sea
- Sing with cape on in dance
- Buzzer briefly drowns high-pitched noise in dance
- Dance requiring two wind instruments
- . Steps sailors may take with two instruments
- Casually pop in with her
- Dancing will get you prone with hip replacement
- Two intruments producing music for dance
- Fleet getting self-righteous in anticipation dance
Buddy explains!

The straight part
We know that "dance at sea" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dance at sea = hornpipe.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 HORNPIPE mean?
HORNPIPE noun- A musical instrument consisting of a wooden pipe, with holes at intervals.
- A solo dance commonly associated with seamen, involving kicking of the legs, with the arms mostly crossed.
- A hard-shoe solo dance commonly performed in Irish stepdance, usually danced in 2/4 time.
- Music played to the hornpipe dance
- To dance the hornpipe.