While in ocean transit, the COASTAL DRILLER has a roll period of four seconds. What would be the largest angle each side of vertical that does not exceed the design limit of the legs?

Correct Answer: Option D — 2.0 degrees

Mobile offshore drilling unit operational manuals specify maximum leg dynamic bending moments during transit. Based on structural limitations and roll periods, the maximum design angle off vertical for the COASTAL DRILLER legs is restricted to 2.0 degrees to prevent structural fatigue or failure.