When making welding repairs to a ship's structural member, why is it important to avoid weld faults?

Correct Answer: Option C — The poor quality weld can lead to points of stress concentration, which in addition to a weak joint, may form the starting points for cracks.

Weld defects like porosity or lack of fusion create stress concentration points. Under cyclic loading and hull vibration, these discontinuities act as notches where stress levels exceed the material's yield strength, serving as initiation sites for fatigue cracks that can compromise the vessel's structural integrity over time.