How Boats Float explores the science of buoyancy, revealing why massive ships stay afloat while small objects sink. The book centers on Archimedes' principle, explaining how an object's weight relative to the fluid it displaces determines whether it floats. Understanding density and specific gravity is also crucial, as variations in these properties dictate buoyancy outcomes, impacting ship design and beyond.

The book progresses from fundamental principles to practical applications, dedicating chapters to Archimedes' principle, density's role, and ship/submarine design. It uniquely integrates historical context, scientific rigor, and engineering applications, moving beyond theory to demonstrate real-world usage.

The approach includes experimental data, historical accounts, diagrams, and illustrations to visually demonstrate key concepts, providing a comprehensive understanding of fluid mechanics.