Aloha - if arriving outside this port! (5)
I believe the answer is:
haifa
'this port' is the definition.
(I've seen this before)
'aloha if arriving outside' is the wordplay.
'outside' indicates a hidden word (a word is around or outside the answer).
'HAIFA' is hidden in the letters of 'aloha if arriving'.
(Other definitions for haifa that I've seen before include "Seaside city" , "Israeli city" , "Middle East city" , "Major Israeli port" , "Seaport in Israel" .)