While drilling loaded as shown in Sample Load Form #4 (Drilling), the DEEP DRILLER suffers a sudden unexpected inclination to port and aft. Strong winds and high waves are from the starboard bow. Among the possible causes, you should consider __________.

Correct Answer: Option B — failure of mooring lines 3 or 4

Environmental forces from the starboard bow place high tension on windward moorings. A sudden inclination to port and aft under these conditions strongly indicates the failure or slippage of weather-side mooring lines 3 or 4, causing the mobile offshore drilling unit to shift.