A couple of weeks ago I swam 10km. Yes, that’s right. 10km or 10000m if you prefer. And yes, it was hard work. To be honest I think I am still in shock after it, so if you ask me if I will do it again, at this moment the answer is… No way!! However, swimming my first long distance race in a lake has lots of advantages, and one big disadvantage. Some of the good things about fresh water is, for example, being less aggressive to your skin, your eyes, you mouth, and believe me, when you expend more than 4h in the water, that is a bonus! Another good thing is that if you are thirsty, you can always take a sip between strokes. The irrational fear to be eaten by a shark instantly disappears, there is nothing that can kill you in a lake, or so I have been said… However, there is a huge disadvantage; half way to the race, conditions changed, and what was a flat lake became a rough annoying choppiness. I normally enjoy swimming in rough seas, it gives another dimension to the swim. But in the race day my only thinking was, “I could def. do with a little less chop” and I could not understand why. Until it literally sunk on me, you are less buoyant on fresh water!!!
Buoyancy is defined by a few things, and one of them is the density if the fluid you are immersed in, in this case fresh water. If you make the numbers (ask me if you are curious) the results is that, in fresh water, approx 3% more of your body is less submerged than in salt water. Yes, I know, it doesn’t look very impressive, but believe me, when you are swimming 10km everything counts!!
Have you ever noticed the difference between salt and fresh water? Did you ever think one of the reasons could be buoyancy?