If a thruster that has been running for hours at 45% shows a drop to 20% feedback, what will happen to positioning ability?

The correct answer reflects the understanding that a drop in feedback from a thruster does not immediately result in a loss of positioning ability. In a dynamic positioning (DP) system, thrusters are responsible for maintaining a vessel's position against external forces such as wind, waves, and current. If a thruster has been operating effectively at a certain percentage — in this case, 45% — and its feedback reduces to 20%, it indicates a change in performance, but it does not automatically compromise the overall positioning ability of the system.

It's important to note that a DP system is designed to utilize multiple thrusters, and the remaining thrusters may still provide sufficient power and control to maintain positioning, depending on the overall configuration and load conditions. The system typically has built-in algorithms that can compensate for variations in thruster output to some degree. Thus, a single thruster dropping to 20% feedback might lead to a reduced effectiveness, but it does not imply an immediate loss of positioning capability.

In practice, the implications of such a feedback drop would need further investigation and monitoring, as the system might still be capable of adapting to maintain vessel position until corrective actions can be taken to address the thruster's performance.