What drainage system is responsible for de-watering forward and aft of the main machinery spaces?

The correct answer is the vertical drainage system. This system is specifically designed to manage and control water accumulation around critical areas such as the main machinery spaces, both forward and aft. Its primary function is to prevent water from pooling, which could potentially lead to operational issues or damage to machinery and equipment.

A vertical drainage system efficiently removes water by directing it vertically upwards or through dedicated channels that lead to designated drainage points. This is crucial in machinery spaces where water can pose risks such as corrosion, electrical hazards, or impairment of mechanical operations.

In contrast, other systems mentioned serve different purposes. The shore drainage system typically manages water run-off when the vessel is docked, focusing on water outside the ship. The emergency drainage system is designed for rapid response in case of flooding or emergencies, often activated only under critical conditions. The auxiliary drainage system usually refers to support drainage mechanisms that assist other systems but is not primarily designated for the specific function described in the question.