What type of door is primarily used in areas exposed to water?

The primary function of a watertight door is to provide an effective barrier against water ingress in environments that are exposed to moisture or flooding. These doors are specifically designed with features that ensure a tight seal when closed, preventing water from passing through even under pressure. This is essential in maritime applications, industrial settings near water sources, and other areas where exposure to water is a significant concern.

In contrast, standard doors are not designed to resist water and can deteriorate or fail in wet conditions. Fire doors, while important for preventing the spread of fire and smoke, do not offer the necessary protection against water damage. Access doors, often used for maintenance and inspection purposes, do not provide the watertight features required in areas exposed to water. Therefore, watertight doors are crucial in these specific environments to maintain safety and structural integrity.