A number of directors at sea (6)
I believe the answer is:
aboard
'a number of directors at sea' is the definition.
I can't tell whether this defines the answer.
'directors at sea' is the wordplay.
'directors' becomes 'board' (board of directors).
'at' says to put letters next to each other (I've seen this in other clues).
'sea' becomes 'a' (I can't justify this - if you can you should give a lot more credence to this answer).
'board' put after 'a' is 'ABOARD'.
Can you help me to learn more?
(Other definitions for aboard that I've seen before include "on gig, perhaps?" , "on a yacht maybe" , "on a train, perhaps" , "On (a ship, train, etc)" , "on a plane, perhaps" .)