Do you sometimes like to play detective when looking at water and figure out who or what caused certain pattern on the surface? Then I’ve got a nice riddle for you today!

Where do all those lines parallel to the pontoon come from?

Look at the picture below. Do you see all those parallel lines this side of the pontoon? Any idea what might have caused them?

Hint: The pontoon is floating on the water, and sometimes this happens: Ships pass by.

And when ships come by, they make waves, and then it looks like this:

(full disclosure: As you might or might not see from the waves on the far side of the pontoon in the picture above is that the ship that caused those waves was going into the locks (so right to left) in contrast to the ship in the picture above this one, where the ship went out of the canal and into the Kiel fjord…)

But yes! Ships make waves, which then move the floating pontoon, and with its edge the pontoon generates those long straight wave fronts, one after the next, so they propagate out as parallel lines, following each other!

Sometimes also this happens:

Going the wrong way round without any issues! I like tugs, they are just really really cool and I want to drive one some day.

But even without tugs in sight, Kiel is a super nice place to live in…

Happy Sunday evening, everybody! :-)