Fresh water and Seawater Density
A liquid has a certain volume and weight and will take the shape of its container. To the diver the most important liquid is water. For all practical determinations water can be measured as being incompressible, and, in the context of this article, the changes in volume or density caused by temperature changes can be ignored. Therefore:
Density (freshwater) = 1000 kg/m3
Seawater differs in density in the different oceans of the world, depending on the amount of dissolved matter (mainly salt) in it. For example, in some parts of the Baltic, the water is nearly fresh, while in the Red Sea, the salt content is very high and so, therefore, is the density. For all practical purposes, and the purposes of this article, the average density can be used:
Density (sea water) = 1030 kg/m3
Conclusion:
The density of fresh water is 1000 kg/m3 and can be considered incompressible for practical purposes. On the other hand, the density of seawater varies in different oceans due to the varying amount of dissolved matter, primarily salt. The average density of seawater is approximately 1030 kg/m3.
