What action should be taken if the overfill alarm is triggered on a tankship?

When the overfill alarm is triggered on a tankship, the appropriate action is to immediately stop discharging. This alarm indicates that the tank is approaching its maximum capacity, and continuing to discharge could lead to a spill, which poses significant environmental and safety risks. Stopping the discharge allows the crew to address the situation without further increasing the tank's contents, ensuring safety and compliance with regulations designed to prevent spills.

Taking no action or continuing operations as usual could exacerbate the situation, leading to potential overflows. Increasing the pumping speed would also be inappropriate, as it would only hasten the filling of the tank and increase the risk of overflowing. Checking fuel reserves, while an important task in other scenarios, is irrelevant in the context of a triggered overfill alarm and does not address the immediate danger. Therefore, halting discharge operations is the most effective and safe response to this alarm.