Question 1

Your DP2 vessel needs to open the bus tie before commencing DP field operations. The chief engineer advises it will take 45 minutes to complete a power rebalance and safely open the bus. The vessel manager calls and says the client is furious about the delay — can the master just approve operating on closed bus 'briefly' inside the field?

As master, what is the correct decision?

Accepted Answer

Decline to approve closed bus DP operations inside the field. The 45-minute delay is a scheduling cost; a common cause failure on closed bus inside the field is a safety event with consequences potentially including total loss of DP, collision with the installation, and environmental damage. Commercial pressure is not a safety justification. The master's accountability to the ISM Code and the SMS cannot be commercially overridden IMCA DPE 01/23 documented incidents directly caused by closed bus DP operations approved under commercial pressure. The ISM Code (Article 5) places safety management responsibility on the master, who has explicit authority to make decisions regarding safety and prevention of pollution regardless of commercial implications. A master who approves closed bus DP operations because a vessel manager says "the client is furious" has allowed the commercial pressure to penetrate the safety management system — exactly what the ISM Code is designed to prevent. The 45 minutes is the cost of the schedule; it is not the cost of the risk.

Question 2

Reviewing the DP operations file, you discover that the last three-day operation completed yesterday had no formal ASOG signed by the client and master — the DPOs were working to verbal limits agreed informally between the lead DPO and the installation rep.

As chief officer, what are your responsibilities in this situation?

Accepted Answer

Report the finding to the master, raise it through the SMS non-conformity process, and ensure a formal ASOG is in place before the next DP operation. The absence of a signed ASOG means the operation ran without the agreed, documented limits that protect the vessel, client, and crew — if an incident had occurred, liability and insurance implications would have been significant. Completing without incident does not mean the risk was acceptable An operation conducted without a formal ASOG has operated without the documented, agreed safety envelope that both parties have confirmed they understood and can execute. Verbal limits are not equivalent — they cannot be referenced in an incident investigation, may be recalled differently by each party, and do not bind the installation authority in the same way a signed document does. IMCA M109 requires the ASOG to be agreed and documented before operations commence. A retroactive document is not honest reporting. The correct response is to report the non-conformity, understand how it happened (was the ASOG template not available? Was there time pressure?), and close the systemic gap.

Question 3

You are master of a DP2 anchor handler. The client representative has asked you to hold a position alongside a semisubmersible in conditions that your current capability plot shows exceeds your vessel's capacity from the prevailing weather direction by approximately 6 knots. The client says another vessel did it last week.

How do you handle this situation?

Accepted Answer

Decline, explaining clearly that the capability plot shows the vessel cannot maintain DP2 position in the prevailing conditions from that direction — what another vessel did in possibly different conditions is not a basis for overriding your own vessel's demonstrated limits. Offer alternatives: a different heading if the worksite permits, waiting for conditions to improve, or conducting the operation under manual dynamic positioning with full risk assessment The capability plot defines the vessel's actual physical limits — beyond it, the DP system cannot maintain position, and the master's responsibility is to the vessel, crew, and installation. "Another vessel did it last week" is irrelevant: different vessels have different capability, last week had different weather, and the other vessel may itself have been operating unsafely. Passing written responsibility to the client does not discharge the master's legal duty of care. The master's professional obligation is to decline and explain — which also protects the client's installation. Offering alternatives is constructive; refusing without options creates unnecessary conflict. The master's authority to decline an unsafe operation is absolute and non-delegable.

DP — What-If (Master/C-O) Practice Questions