Battling the currents
Hi HIW, I have started swimming now that the sea is warmer. As I swam out to sea and back again, I noticed that one way was quicker than the other, notably due to the current. The next day this direction changed, and I assumed it was because of the wind blowing in one direction. However, after more swimming on calm days, the direction of the current still changes. What causes these changes?
The more you encounter the sea, the more you will become aware of its ever-changing character. Its current is one of the elements that often changes, and the surprising strength can be very dangerous if you are unaware of its movements. You are right in suspecting that the wind impacts these movements. Global winds are a major cause as they move the water to create surface currents. However, this is not the only factor in the currents’ speed and direction, and the wind alone won’t always tell you the sea’s conditions. Temperature as well as salt fluctuations at sea can bring on a surge in current. When the sea water becomes more or less dense it rises and sinks, impacting the movement of surrounding water. Cold water or salty water is more dense, and as it moves down, water will be pushed up from below and stir up your swim.