🔍 Key Concepts

• ballast and why it is used on barges and ships • difference between free surface effect and overall stability • how liquid moving in partially filled tanks affects a vessel

💭 Think About

• Think about the main safety reason for adding ballast before sailing: what are we trying to improve or control on the vessel? • Which choice describes a problem that ballast is actually used to reduce, and which one describes the positive condition we want to achieve? • Consider what happens to a vessel’s center of gravity and righting ability when you add ballast low in the hull.

✅ Before You Answer

• Identify which option describes the primary safety benefit of proper ballasting. • Check which answer mentions a desired condition, not a side-effect or a restriction. • Recall that partially filled tanks can worsen stability; ask how proper ballasting is used in practice to deal with that.