WordWeb Online

1. Away from shore; away from land
   "cruising three miles offshore"

1. (of winds) coming from the land
   "offshore winds";
   - seaward
    
2. At some distance from the shore
   "offshore oil reserves"; "an offshore island"
    
3. Located in another country, esp. one having low rates of tax
   "an offshore bank account"

See also: marine

Antonym: inshore, onshore

Encyclopedia: Offshore