Floating ships made out of iron...

It is clear to everybody that a solid steel block cannot float. But why is it possible that ships made out of steel can cross the ocean?
In the picture below you see a solid steel block and a ship made out of steel, both put on a huge scale. The scale shows that both weigh the same.

But the volume of the ship is much greater than the volume of the solid steel block!
If we looked through the walls of the ship we could see that inside the ship there are many empty spaces (see picture below).

Because of the hollows (cabins, store rooms etc.) the ship has a greater volume than the solid steel block although they are equal in their weight. Because of the greater volume the ship displaces

• more water
• less water
• the same amount of water

in comparison to the steel block.