When patching a leak around a round hull hole, which patch technique is commonly used?

• A. Circular Canvas Patch
• B. Patch Plate
• C. Circular Canvas Patch with Sealant
• D. Patch Plate with Sealant

Answer: (D)

For this scenario you need a repair that is rigid, distributes the water pressure, and seals watertight around the opening. A patch plate with sealant fits that need best. The metal plate covers the hole completely and is bolted to the surrounding hull, spreading the load over a larger area so the hole won’t propagate or deform under pressure. Applying sealant along the edge fills any gaps between plate and hull, creating a reliable barrier against water intrusion.

A circular canvas patch, even with sealant, is less durable because canvas can deform under hydrostatic pressure and won’t distribute the load as effectively as metal. It’s typically a temporary or emergency measure when a patch plate isn’t available. The same idea with a patch plate is the standard, robust repair for a round hull hole.