When you place a solid ball of steel into water, it will immediately sink because the density of steel (7.8 g/cm3) is greater than the density of water (1.0 g/cm3). So, you may be wondering why huge steel ships are floating around the world. Well, it involves some basic math and science knowledge...and common sense.
Inspect the steel ship for any holes. Holes will make your steel ship sink, because they let water flow through and flood the deck.
Make sure the boat is hollow. To make steel float, the average density must be reduced. Thus, make the steel boat hollow by adding a boiler room or living quarters. This will expand its volume without changing the mass.
Design the steel ship to be under 1.0 g/cm3 buoyancy. This allows for cargo to be loaded into the hollow area of the ship. When cargo is placed in a boat, its average density increases. The boat has to sink deeper and displace more water while increasing the buoyant force.
