Why is it easier to swim in the sea than in a pool?

Saltwater is heavier than fresh and therefore makes objects float. The greater the concentration of salt in the water the greater its buoyancy will be. A Swimmer can float better in saltwater and can therefore swim more easily due to this buoyancy . The Great Salt Lake in Utah and the Dead Sea in Jordan in the Middle East are so salty that fish cannot live in them , and a swimmer cannot stay below the surface.