Imagine you're on a large ship, cruising across the vast ocean. Suddenly, there's a breach in the hull, and water starts pouring into the ship. What do you think will happen? The ship will start to sink, right? But, does the whole ship sink immediately? Thanks to the architecture of modern ships, the answer is no. The ship is divided into several watertight compartments or 'bulkheads'. If water floods one compartment, the others remain unaffected, at least for some time, buying valuable time for rescue efforts.