Sea water

Sea water is water from a sea or ocean. On average, sea water in the world's oceans has a salinity of ~3.5%. This means that for each 1 liter (1000mL) of sea water there are 35 grams of salts (mostly, but not entirely, sodium chloride) dissolved in it. This can be expressed as 0.6M NaCl. Water with this level of osmolality is, of course, not potable.
Sea water is not consistently saline throughout the world. The planet's freshest sea water is in the Gulf of Finland, part of the Baltic Sea. The most saline open sea is the Red Sea, where high temperatures and restricted circulation result in high rates of surface evaporation and there is little fresh inflow from rivers. The salinity in isolated seas can be considerably greater.
The density of sea water is between 1020 and 1030 kg/m3. Due to chemical buffering, seawater pH is limited to the range 7.5 to 8.4.