Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
offshore [ɔfˈʃɔːr] adj (oilrig, fishing) морско́й
there was a gentle offshore breeze на мо́ре дул лёгкий бриз
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.