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Why can a steel ship float even though steel is denser than water?

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Portrait of Archimedes by Giuseppe Nogari shows an elderly man with white hair and beard, holding a compass, gazing downward, set against a dark background. — Archimedes Archimedes, oil on canvas by Giuseppe Nogari, 18th century; in the Pushkin Fine Arts Museum, Moscow. Archimedes was an ancient Greek mathematician and inventor.

A steel ship floats because of Archimedes’ principle, which states that any object submerged in a fluid is acted upon by an upward buoyant force equal to the weight of the fluid it displaces.12

While steel is denser than water, a ship is not a solid block of steel. It is carefully designed with a large, hollow hull that encompasses a significant volume of air. Because the ship’s total volume is very large relative to its mass, its average density—including the steel, cargo, and the air inside—is less than the density of water.3

When a ship is launched, it sinks into the water only until the weight of the water it displaces is exactly equal to its own total weight. As long as the ship is shaped to displace a weight of water greater than or equal to its own weight, it will remain buoyant. Naval architects meticulously calculate these volumes and weights to ensure the ship floats at the intended depth.13