Alternatively get a paddle (3)
I believe the answer is:
oar
'paddle' is the definition.
(I've seen this in another clue)
'alternatively get a' is the wordplay.
'alternatively' becomes 'or'.
'get' means one lot of letters goes inside another.
'or' enclosing 'a' is 'OAR'.
(Other definitions for oar that I've seen before include "Propelling blade" , "Pole for rowing" , "Rower's implement" , "that may be feathered?" , "Crew member" .)