Surf is finally up around Maine (5)
I believe the answer is:
spume
'surf' is the definition.
(I've seen this before)
'is finally up around maine' is the wordplay.
'finally' indicates one should take the final letters.
'around' says the letters should be written backwards.
'maine' becomes 'me'.
The last letter of 'is' is 's'.
'up' in reverse letter order is 'pu'.
's'+'pu'+'me'='SPUME'
(Other definitions for spume that I've seen before include "Foam on waves" , "Sea foam, froth" , "Surf" , "Froth on waves" .)