What is the most probable reason for a sudden high increase in DP current Residual Force on a PSV alongside an installation?

A sudden high increase in the DP current Residual Force on a Platform Supply Vessel (PSV) during an installation phase typically indicates an issue with position reference systems. When one of the position reference systems is unreliable, it can lead to discrepancies in the information being used by the Dynamic Positioning system to maintain the vessel's position. The DP system relies heavily on accurate position data to calculate the necessary thruster response to keep the vessel stable and on course. If one of these references becomes compromised or fails, the DP system may overcompensate or react inappropriately to maintain position, resulting in a spike in the residual force.

In contrast, reliable position reference systems would provide consistent and accurate data to the DP control system, thus preventing such spikes in residual force. Incorrect thruster settings could lead to performance issues, but typically would not specifically result in a sudden high increase in residual force—it would rather cause a steady deviation from the desired position. Violating operational guidelines might affect various aspects of DP performance, but again, it would depend on the specific guidelines breached and wouldn’t directly imply a sudden spike in residual force due to reference malfunction. Therefore, the most logical and probable explanation for a sudden increase in Residual Force during an operation is due