Final answer:
Compared to fresh water, a ship displaces less volume of salt water because salt water is denser, which means the ship will float higher in salt water.
Step-by-step explanation:
When a ship floats in both fresh water and salt water, the volume of water displaced in the salt water is less compared to fresh water. This is because salt water is denser than fresh water. According to Archimedes' Principle, an object submerged in a fluid will displace a volume of fluid equal to its own weight. Since salt water is denser, a ship doesn't need to displace as much volume of water in saltwater to equal its weight and achieve buoyancy. This is the main reason why a ship will float higher in salt water than in fresh water.