During a flooding casualty, checking watertight fittings is essential primarily for what reason?

The primary reason for checking watertight fittings during a flooding casualty is to prevent further flooding. Watertight fittings are designed to keep water from entering certain compartments of the vessel, and ensuring these fittings are secure and functioning properly is crucial when addressing an existing flooding situation. If watertight fittings are compromised or malfunctioning, water can continue to infiltrate the vessel, exacerbating the situation and potentially leading to more severe damage or instability.

In scenarios where flooding is present, immediate action to secure these fittings is essential in order to contain the floodwater, allowing the crew to focus on remediation efforts, such as deploying pumps or making repairs, without the constant threat of additional water inflow. This proactive measure is critical in maintaining the safety and integrity of the vessel amidst an emergency.