It is located just west of Sark and has a surface area of about 200 a. It is located just west of Sark and has a surface area of approximately 200 a. Sark claims it as a tenement , and the Ministry of Justice , the department of the United Kingdom government with responsibility for the Channel Islands , considers Brecqhou part of Sark - but this is disputed by Brecqhou 's current tenants .