The seamen went outside by themselves for seafood (8)
I believe the answer is:
abalones
'for seafood' is the definition.
(I've seen this before)
'the seamen went outside by themselves' is the wordplay.
I cannot quite understand how this works, but
'by themselves' could be 'alone' (I've seen this in another clue) and 'alone' is present in the answer.
'seamen' could be 'abs' (AB is a naval abbreviation for able seaman) and 'abs' is found within the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for abalones that I've seen before include "seafood" , "Sea food" , "Moluscs with ear-shaped shells, pearly interiors" , "Edible molluscs" , "Abo leans out to get shells lined with mother-of-pearl" .)