Material in Albany longboat (5)
I believe the answer is:
nylon
'material' is the definition.
(nylon is a kind of material)
'in albany longboat' is the wordplay.
'in' indicates the answer is hidden within the clue.
'NYLON' is hidden within 'albany longboat'.
(Other definitions for nylon that I've seen before include "Polyamide" , "Hose" , "Cover for leg" , "Type of material" , "Artificial yarn/fabric" .)