Vessels answer with speed, oars flying (8)
I believe the answer is:
amphoras
'vessels' is the definition.
(amphora is a type of ancient jug)
'answer with speed oars flying' is the wordplay.
'answer' becomes 'a' (abbreviation eg in Q and A).
'with' indicates putting letters inside.
'speed' becomes 'mph' (miles per hour).
'flying' indicates an anagram.
'oars' with letters rearranged gives 'oras'.
'mph' placed within 'oras' is 'mphoras'.
'a'+'mphoras'='AMPHORAS'
(Other definitions for amphoras that I've seen before include "Ancient two-handled jars used to hold oil or wine" , "Tall ancient Greek or Roman vases" .)