What is the only authority that can approve the blanking of soot blowers?

The correct answer is NAVSEA because it holds the responsibility for overseeing the construction, maintenance, and repair of naval ships and submarines. This includes ensuring proper procedures are followed for equipment operations, which encompasses the management of soot blowers. Soot blowers are critical for maintaining the efficiency of boiler systems by removing soot buildup, and their blanking is a significant operation that requires proper authorization to ensure safety and compliance with operational standards.

NAVSEA's involvement ensures that such actions do not compromise the integrity of the ship's systems or lead to safety hazards. Other authorities, while they may have various operational and administrative roles, do not have the specific authority to approve the blanking of soot blowers, which is a technical decision governed by standards and regulations set forth by NAVSEA.