Tastes discovered by sailors at the back (6)
I believe the answer is:
astern
'at the back' is the definition.
(I've seen this before)
'tastes discovered by sailors' is the wordplay.
'discovered' means to look at the middle letters.
'by' is a charade indicator (letters next to each other).
'sailors' becomes 'rn' (abbreviation for Royal Navy).
The middle of 'tastes' is 'aste'.
'aste'+'rn'='ASTERN'
(Other definitions for astern that I've seen before include "Toward the tail of a vessel" , "Aft" , "Backward" , "following behind vessel" , "back for sailors" .)