Corrosion under the area covered by the seizing wire can cause breast lines to suddenly break. As seizing wires can prevent proper inspection and lubrication of wire rope mooring lines, it may be better to choose a different solution all together.
A recent Mars Report describes a breast line breaking due to corrosion. Although without consequences, the company involved chose to to replace the socket type fittings with swaging/mechanical eye splice type at the upcoming dry dock. A transcript of the incident:
An LNG vessel was at berth and loading under some sea swell conditions. Sixteen lines had been used to secure the vessel. One of the aft breast lines (line no 13, shown in red below), a galvanised steel wire rope, parted. The incident was without consequences and the line was replaced with a spare.
The company investigation found that there was corrosion under the area covered by the seizing wire near the socket type fitting.