What should be investigated when an underwater explosion occurs alongside or close aboard the ship?

• A. Voids/Tanks & lower compartments
• B. Upper decks
• C. Engine room
• D. Mast and rigging

Answer: (A)

When an underwater explosion occurs near a ship, the first concern is the hull’s watertight integrity in the lower part of the vessel. Water entering through the hull below the waterline will flood the spaces that provide buoyancy. The voids, ballast tanks, and other low-lying compartments are most critical because flooding of these areas directly reduces buoyancy and can quickly affect stability and trim. By inspecting these spaces, you can determine the extent of flooding, identify which compartments are compromised, and begin control actions such as isolating ruptured sections with bulkheads and valves and pumping out water. Upper decks are above the waterline and less prone to immediate flooding, and while the engine room could be affected if damage extends, the priority is the lower compartments that govern buoyancy.