🔍 Key Concepts

• Slack tank behavior – how liquid in a partially filled tank responds when the shell plating is breached below the waterline • Double bottom tank location – where it sits relative to the outside seawater and the ship’s baseline • Hydrostatic balance – relationship between tank liquid level and outside seawater level when there is a hole

💭 Think About

• Picture a side view of the ship: where is the double bottom tank, and where is the sea surface relative to the top of that tank? • If the tank is slack and holed to the sea, what drives water in or out: is it pump pressure, gravity, or difference in water levels (head)? • As time passes after the hole, would the liquid inside try to match the level of the sea outside, stay as it was, or do something random?

✅ Before You Answer

• Identify whether the hole is below or above the outside waterline – this is critical. • Decide whether sea pressure at the hole is greater than, equal to, or less than the pressure from the liquid already in the tank at that depth. • Think about the condition after repeated soundings, meaning long enough for levels to approach equilibrium, not just the first few minutes.