🔍 Key Concepts

• reserve buoyancy in basic ship construction and stability • difference between spaces above and below the load waterline • meaning of enclosed and watertight spaces on a vessel

💭 Think About

• Ask yourself: Is reserve buoyancy about spaces that are already in the water, or about extra volume that can be used to keep the ship afloat if it gets heavier or flooded? • Which parts of the ship contribute to staying afloat when loaded more deeply: spaces above the current waterline, or slack/partially filled tanks below it? • Think about how a ship sinks: what volume must be lost (filled with water) before the vessel actually loses its ability to float safely?

✅ Before You Answer

• Identify which options clearly refer to space above the waterline versus below the waterline. • Check which choices describe spaces that are enclosed and watertight and currently filled with air, not water. • Eliminate any choices that confuse percentage flooded or slack tank volume with the total extra buoyant volume available to keep the ship afloat.