What type of equipment is primarily used to seal holes in the hull?

The primary equipment used to seal holes in the hull consists of patching kits and plugs. These kits are specifically designed for damage control scenarios where a vessel might sustain hull breaches. They typically include items such as flexible patch materials, sealants, and various types of plugs, which can be used to effectively create a watertight seal over a hole in the hull.

The materials in these kits are constructed to withstand water pressure and are meant for emergency situations, making them essential for immediate response during an incident such as flooding or leaks. The ability to quickly patch a hole can prevent further water ingress and stabilize the vessel until more permanent repairs can be made.

Other options, while useful in different contexts, do not serve the specific function of sealing hull breaches as effectively as patching kits and plugs. Fire extinguishers are necessary for dealing with onboard fires but do not provide a solution for hull integrity. Ropes and chains may assist in securing materials or providing temporary holds but lack the sealing capability required for water-tightness. Water-filled bladders can be used for stabilizing or compartmentalizing but are not specifically designed for patching holes.