I presume you mean the saltiest or the most saline sea water in the world. Dead Sea,a lake on the border of Israel and Jordan is the saltiest area of water in the world. Located in the Great Rift Valley, its depth lies 1,292 feet below the sea level. Its water has a salinity of 25 percent, which is nearly 5 times saltier compared to sea water. No swimmer can sink or drown in this water because the chemical properties of Dead Sea make the water buoyant. The color of the water changes according to the water, but it is usually blue.