The Atlantic and Pacific Oceans are often cited as bodies of water that appear not to mix.
While technically oceans and not seas, the phenomenon often attributed to two "seas" not mixing usually refers to the visual effect seen where the Atlantic and Pacific Oceans meet. This is observable due to differences in water density, salinity, and sediment content. The differing properties create a visible line where the waters meet but don't immediately blend. Videos often showcase this "separation line" between the bodies of water.
It's important to note that while a distinct boundary may be visible, the waters do eventually mix over time through currents and diffusion. The visual effect is a result of differing properties, not a complete and permanent barrier. Therefore, a more accurate statement would be that the Atlantic and Pacific Oceans appear not to mix immediately where they meet.
