Explorer and crew taking a set line (8)
I believe the answer is:
magellan
'explorer' is the definition.
(Magellan is an example)
'crew taking a set line' is the wordplay.
'crew' becomes 'man' (both can mean to staff or operate something).
'taking' means one lot of letters goes inside another.
'set' becomes 'gel' (both can mean to harden).
'line' becomes 'l' (used when specifying particular lines from a poem).
'a'+'gel'+'l'='agell'
'man' placed around 'agell' is 'MAGELLAN'.
'and' acts as a link.
(Other definitions for magellan that I've seen before include "Portuguese navigator who crossed the Pacific" , "Ferdinand -, Portuguese navigator" , "Portuguese navgator" , "Port. explorer; a S. Am. Strait" , "S American strait named for 16th century Portuguese explorer" .)