OVERVIEW , OF A SINGLE POINT MOORING - SBM - USED FOR LOADING AND/OR DISCHARGING OF CRUDE OIL , IN THIS CASE BEING LOCATED AT BONGA - NIGERIA - USED FOR LOADING ONLY , VESSELS MOOR TO SBM VIA A CHAIN PASSING THROUGH PANAMA FAIRLEAD AND LOCKED ONTO A BOW CHAIN STOPPER ON BOW FORECASTLE.