Who is responsible for maintaining an engineering log when the vessel is underway?

The Engineering Officer of the Watch (EOOW) is primarily responsible for maintaining the engineering log while the vessel is underway. This role is crucial, as the EOOW serves as the operational officer during a designated watch, overseeing the machinery and systems on board the vessel. Keeping an accurate and detailed engineering log is essential for documenting operational parameters, any noteworthy events, and maintenance activities that occur during their watch.

This log is vital for ensuring safety and compliance with maritime regulations, as well as providing valuable information for the vessel's crew in terms of its performance and any concerns that may arise during the journey. The EOOW's direct involvement in the day-to-day operations and their responsibility for monitoring critical engine performance makes them the most suitable individual for this task.

Other roles might have various oversight responsibilities or may be involved in the maintenance of records, but their focus is typically on broader or more specialized duties that don't directly relate to the continuous logging of the engineering conditions during a watch.