Question 352General Subjects - 1st Asst/Chief

The correct answer is C) Hull thickness measurements. The hull thickness measurements are required by the vessel's class society (e.g., American Bureau of Shipping, Lloyd's Register) as part of the special survey. This is to ensure the hull's structural integrity and identify any areas of excessive wastage or corrosion that may need repairs or renewal. The other options, such as bow thruster overhaul, scavenging air box inspection, and replacement of sea valves, are routine maintenance items that may be required, but they are not specifically mandated by the class society as part of the special survey requirements.