Container ships do not sink because of buoyancy. Ships made of steel are constructed in a very special way so that they do not sink. The weight of water displaced by the hull of the ship must be greater than the weight of the ship (along with the load it is carrying). As a result, the water below the ship pushes it upwards with a force known as buoyancy. We also experience buoyancy when we swim and feel lighter in water than on land. Floating tires increase the buoyancy further. In contrast, submarines must overcome the buoyancy in order to sink. For this, special tanks are flooded with water.
