🔍 Key Concepts

• Reserve buoyancy and what happens when a compartment is open to the sea • The difference between free communication with the sea and normal internal free surface effect (like slack tanks) • How flooding in one compartment affects transverse stability (ability to resist heeling)

💭 Think About

• Visualize a watertight compartment that now has a hole to the outside: does it still help keep the ship afloat, or does it behave more like the surrounding sea? • Compare free surface in a closed tank vs. water that can move freely in and out to the ocean level—how does that affect the ship’s metacentric height (GM) and righting ability? • Ask yourself: does a single partially flooded compartment automatically sink a ship, or does it mainly change how stiff or tender the ship is?

✅ Before You Answer

• Verify what reserve buoyancy means: "enclosed volume above the waterline that can contribute to flotation if flooded" • Recall that free surface effect normally refers to liquid moving inside enclosed spaces—check how that differs from free communication with the sea • Consider whether the most immediate and certain effect of partial flooding with sea connection is on stability or on total buoyancy/sinking