Inflatable Lifeboats

When an inflatable lifeboat is fully inflated, the internal pressure on the hull constantly searches for its weakest point. This weak point is the opening for personnel and supplies to enter and exit. If the opening is made with a regular zipper, air pressure will hiss and leak from the gaps in the zipper teeth. When waves come in, water rushes in through the gaps, and the entire boat instantly loses buoyancy. A metal airtight zipper, specifically designed for extreme water conditions, transforms the soft hull opening into a rigid, sealed bulkhead under the dual impact of high-pressure air and raging waves. It doesn't use rubber teeth, but instead chooses metal—not for weight, but to achieve terrifying locking strength and indestructible mechanical stability. How does it achieve both airtightness and waterproofing? The secret lies in the precise cooperation between the metal teeth and the elastic sealing strip.