Splash! A child sits in an inflatable swim ring, kicking up water on a bright summer day🎠🌊 The ring, the swimsuit and the water are all left open, so children can choose their own colors — and asking what pattern the ring should have is an easy way to start.
A swim ring is filled with air, and air is far lighter than the same volume of water. Ring and air together weigh less than the water they push aside, so the water pushes back harder than they press down and the ring rides on the surface. That upward push is called buoyancy. A steel ship stays up for the same reason: most of the space inside the hull is air, so the vessel as a whole is lighter than the water it displaces.
Is it easier to swim in a pool or in the sea?
Sea water carries dissolved salt, which makes it denser than fresh water, so a swimmer floats a little higher in the sea than in a pool. A pool is still the better place to learn: the depth is marked, there are no waves or currents, and the whole area is easy for an adult to watch. In either one, young children should stay within arm’s reach of a grown-up.
