Step-by-step explanation:
Needles sinks in water due to the more density of needles than the density of water. But ship is made hollow and contains air. So it's average density Is less than that of water. It displaces the liquid of it's own weight causing the ship to float on water.
So, it it possible for iron ships to float on water,but needles sink when dropped in water.
Hope it will help :)❤