At sea, I arrive in coastal region (7)
I believe the answer is:
riviera
'coastal region' is the definition.
(I've seen this before)
'at sea i arrive' is the wordplay.
'at sea' indicates an anagram.
'i'+'arrive'='iarrive'
'iarrive' anagrammed gives 'RIVIERA'.
'in' is the link.
(Other definitions for riviera that I've seen before include "Mediterranean playground of the rich" , "French Mediterranean holiday area" , "Coastal area between Cannes and Italy" , "Med coastal region" , "Nice location" .)