Eight Times a DP Console Did What the Operator Did Not Mean: IMCA Bulletins 2016 to 2025

The Same Mistake, Nine Years Apart

IMCA’s October 2026 bulletin includes a case where a Backup Mode selector, sitting beside the Alarm Acknowledge button, was most probably pressed during an alarm response. It took all thrusters off the DP station. Read in isolation, it sounds like a one-off. It is not. IMCA’s own 2025 bulletin is titled ‘Inadvertent act causes loss of DP, once again!’ This guide gathers eight earlier events, and the October one is the ninth. See the October guide and the Decision Simulator.

The Events

DPE 02/16: Unintentional deselection of a DP control function

During an operation the DPO unknowingly deselected the surge button. The bulletin says the DPO was likely performing multiple tasks at the time. Its advice: consider whether critical switches need additional barriers, because ‘this type of event continues to occur’; use position reference alarm tools to catch movement outside set limits; and avoid significant changes to DP systems during critical phases.

DPE 01/18: Unintentional selection of manual mode

In automatic DP, a double press of the manual position button switched the vessel to manual DP. The main cause was human factors; the secondary one was that the system gave no additional barrier or notification. The bulletin notes similar events on other vessels, and that some operators had fitted covers over mode buttons or made them visually distinct. The operator reported an upgrade to warn the DPO when DP control status changes. Its advice: confirm that an intended action has taken effect, and consider joystick auto heading before going to individual manual thruster control.

DPE 01/18: Unintentional deactivation of the DP system

While in automatic DP, the DP Standby button was activated unintentionally, with no alarm. The control radio handset lay over the DP panel, and Standby needed two presses. Presses so close together that they nearly registered as one could, the bulletin suggests, explain it. The layout forced the operator to lean across the panel to use the VHF, which the bulletin calls poor design. The vessel fitted clear flip-top covers and required the handset to be returned to its cradle.

DPE 03/18: Switching to manual mode caused loss of position

A DP2 platform supply vessel was offloading cargo within 500 m of a fixed platform when a port aft azimuth thruster tripped out of DP. The vessel held position, because that failure was within its designed worst case. Cargo operations stopped and the vessel was ordered out of the zone. The DPO, after consulting the Master, deselected auto DP and switched to manual. The vessel lost position and made light contact with the platform before control was regained.

When auto DP is deselected, the setpoints for the released surge, sway and yaw axes drop to zero, so the thrusters stopped producing force. The DPO did not understand how the system would behave. The bulletin notes that staying in auto DP would likely have let the vessel move clear.

DPE 03/18: Switching from auto DP to IJS mode caused loss of control

A vessel on auto DP was pulling away from a wind turbine transition piece in worsening weather (28 knots). When the DPO switched to independent joystick mode, the setpoints for the deselected axes dropped to zero. The vessel lost control of those axes about 120 m from the turbine, and the wind pushed it back. The crew regained control but could not prevent a collision with the transition piece and its work platform. Testing found no technical defect. The bulletin points to poor situational judgement, limited awareness of the changeover procedure, and recommends revising the DP operations manual, stronger familiarisation and recorded in-field passage planning.

DPE 01/20: Vessel collision with wind turbine

After dropping four technicians at a wind turbine, the vessel held station just outside the 200 m exclusion zone. The OOW left the DP desk for other duties and was alone on the bridge. The vessel was still in DP surge mode and drifted into the turbine about six minutes later at 1.1 knots, damaging the helideck netting and the port bridge wing. No injuries were reported. The OOW had double-tapped a button and did not confirm that full auto DP was active. The bulletin’s lesson: double-pressing is not a reliable way to confirm a mode change, so verify the vessel’s status, and keep bridge manning in line with IMCA M103.

DPE 01/24: Button trouble

While cable laying in a wind farm, a bridge manual override was pressed by mistake. Six thrusters dropped out of DP control and the vessel drifted about 15 m astern under the cable tensioner load, damaging roughly 36 m of cable. The crew regained DP by returning each thruster to DP, and no injuries were reported. The button was a single-action manual override added during a DP control system upgrade as part of a life extension. The bulletin recommends removing or protecting single-action override buttons, testing and training after integrating new systems, updating checklists and Master’s standing orders, and familiarising crews with changes.

DPE 02/25: Inadvertent act causes loss of DP, once again!

During a scrap recovery with an ROV and crane, an alarm sounded. The DPO could not silence it from either alarm panel, and while pressing silence on the forward panel he accidentally pressed the adjacent ‘Take’ button on the DP panel. The vessel was found in manual lever mode. The ROV returned to its management system and the crane lifted off the seabed, quickly, but in a critical phase. Contributing factors were alarm fatigue from consolidated alarm sources, a frozen forward alarm panel that hid the alarm’s origin, and inconsistent silencing methods. The lessons: protective covers or acknowledgement confirmation, reliable alarm panels and reduced alarm load, and the DPO’s open, no-blame reporting was a positive example.

What Runs Through All Eight

• A critical function beside an everyday one. Silence next to Take. Standby under a radio handset. A mode button you press twice.
• No feedback. Several systems gave no alarm or notification when the mode changed. The bulletins repeatedly recommend confirming that an action took effect.
• The moment matters. An alarm response, a multitasking DPO, a critical phase, a solo OOW. These are exactly the times fingers move fast.
• Leaving auto DP is not a neutral act. Two events turned on the fact that the released axes drop to zero setpoints. Knowing what happens to each axis when you change mode is part of the job.
• Design fixes work. Flip covers, visually distinct buttons, a warning when control status changes, and not leaving a handset on the panel.

Test Your Knowledge

Think you've got this covered? Put it to the test in Crew Connect's free Knowledge Checker — try a quick DP/engineering round and see how you score.

Related Reading

• The October 2026 DP bulletins (DPE 03/26)
• The September 2026 DP bulletins (DPE 02/26)