Joy of ultimately untrained boat crew maintaining lead at first (7)
I believe the answer is:
delight
'joy' is the definition.
(synonyms)
'ultimately untrained boat crew maintaining lead at first' is the wordplay.
'ultimately' indicates one should take the final letters.
'boat crew' becomes 'eight' (I've seen this before).
'maintaining' is an insertion indicator.
'at first' indicates taking the first letters.
The last letter of 'untrained' is 'd'.
The initial letter of 'lead' is 'l'.
'eight' enclosing 'l' is 'elight'.
'd'+'elight'='DELIGHT'
'of' acts as a link.
(Other definitions for delight that I've seen before include "Ecstasy" , "Transport - please" , "Give great pleasure to" , "Please highly" , "Greensleeves was mine" .)