Briefly run up to a series of boats (8)
I believe the answer is:
flotilla
'series of boats' is the definition.
'flotilla' can be an answer for 'boats' (I have seen 'many boats' mean 'flotilla' so perhaps 'boats' could also mean 'flotilla'). I am not certain of the 'series of' bit.
'briefly run up to a' is the wordplay.
'briefly run' becomes 'flo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'up to' becomes 'till' (up to or till a certain time).
'flo'+'till'+'a'='FLOTILLA'
Can you help me to learn more?
(Other definitions for flotilla that I've seen before include "set of vessels" , "number of vessels" , "number of small ships" , "collection of vessels" , "Fleet of small craft" .)