Tag Archives: Kiel canal

April weather in September (Great for #WaveWatching and cloud watching!)

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Minutes after drawing the illustration to the “you are not a drop in the ocean, you are the ocean in a drop” quote I shared yesterday in the most beautiful sunshine, the sky started looking like this.

Luckily I had a nice spot from which I could observe what happened next…

…lots of drops. In the ocean. Or oceans in the drops? Who knows. Anyway, after just having done that drop drawing, I couldn’t very well get upset, and I love watching rain on water anyway.

Just look at all the wave rings, and the way drops are catapulted up again only through surface tension!

Here is a (first normal speed, then slow motion) video so you can appreciate it properly, too:

As the rain passed, I found it super impressive to watch the rain showers as they went down elsewhere.

Like over the mouth of Kiel fjord, and I am showing the same spot repeatedly in the following (with more or less the same view, you can use the buoy as point of reference).

I don’t know enough about meteorology to understand what’s going on there, but I can still appreciate the beauty of the rain cloud and how differently things look where it is propagating to (to the right) and where it has already left (to the left).

See how much lower the clouds on the right are, and clearly a different kind of cloud compared to the ones on the left?

At times, it got really dark.

And I watched this one cloud move, continuously raining.

Then there was a dry period of a couple of hours, and when I walked home, it looked like this: Again distinct areas with rain showers.

What I found also really interesting is the swimmer’s wake you see below. There is so much to see in that one picture: The wake, the rain shower in the background, the changing surface roughness from rougher, darker areas, and smoother, lighter areas, and then the areas in the foreground where we can look into the water (see here for why we can do that in some places and not in others)

Same thing as above, only in a different picture…

And again, this time with a really impressive black cloud. And interference pattern in the waves in the foreground.

And now even ring waves that that seagull made…

And as if I hadn’t had enough wave watching in one day, here is a different spot in the afternoon. See the interference pattern as waves get refracted around the bollard?

And, of course, another strong shower came and made us retreat to the inside. But see the rainbow in the picture below? Those are the kind of things that make me really happy! :-)

Spontaneous adventures are the best! Today involving a trip on a historic ship, some sight seeing on Kiel fjord and a bit of Lindy Hop

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I’m lucky to have great friends like Alice, who was spontaneous enough to go on a mini cruise with me today (for which I was only given tickets when I was already on my way to meet her somewhere else). So we boarded the historic MS Stadt Kiel and the adventure began! (Note the Europe flag? Hope you’ve been voting already when you are reading this, otherwise stop reading and go vote! :-))

I had never been on the MS Stadt Kiel before, even though I’ve seen it many times. It’s lovely inside — historic charm and the smell of marine diesel. What more could you want on a gloomy grey Sunday? And a super nice crew of volunteers who run the ship!

Plus we got to see all my favourite spots, like the light house at Holtenau. You also see the pilot station right behind the light house, that’s where the pretty orange pilot ship lives that you see at least in every other of my blogposts ;-)

And the Kiel Canal locks at Kiel Holtenau; looking at them from Kiel fjord. I usually take my pictures either from the shore on the left close to where you see the tower, or from the bridge that you see in the background.

And then, as you do on historic cruises, there was Swing dancing with a dance crew who was performing for us and then even gave us the opportunity to join in, which, of course, Alice and I did. Unfortunately I wasn’t wearing exactly historical costumes, but hey! It was fun! Thanks, Christian! :-)

For privacy reasons as well as for fairness, I had to give everybody the same face that I am making on the picture ;-)

Yep, spontaneous adventures are the best :-)

Windy days at Holtenau locks: Now THAT’s a turbulent wake!

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Now that the weather is nice and sunny again, here is what it looked like only last Saturday. It wasn’t even really stormy, but windy enough so that the ships leaving the locks at Kiel Holtenau were working a lot harder than usual. Especially difficult when you are almost empty and then there is a lot of wind! See that wake?

Right behind the ship you see above, there was a second ship leaving the locks. See how milky the water looks where the first ship went from all the air bubbles that were pushed under water by the ship’s propeller? You can even see some of that water spreading underneath that floating barrier in the foreground!

And see the difference between the waves on the upwind side of the ship and the downwind side?

Here is the picture that my friend sent me that she took from inside of the café that we were sitting in before I HAD to go outside and take pictures. If I am being sent pictures of my back every week by my friends, are they trying to tell me something? :-D

Wave watching at Kiel Holtenau locks

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On Sunday, I set out to see a large cruise liner go through the locks at Kiel Holtenau.

What happened, though, was that a ship with a smiley painted on its deck came first. Do you see the two shadows to the right of the ship, the left one aligning with the one side of the wake’s V? That’s the pillars the bridge is resting on.

This ship has a very interesting wake, since it consists of several Vs. Not quite sure why. Also, it seems to be driving in a very non-straight line, judging by its turbulent wake.

But watch what happens when the wake hits the sides of the canal.

The green thingy interrupts the straight line of the shore and creates these beautiful ring waves!

A little while later they have spread half way across the channel, while on the other side, the wake is just reflected on the shore.

It looks funny how the reflections are so asymmetrical relative to the ship, but of course the ship isn’t driving in the middle of the channel, so they have to be.

And on the other side of Kiel fjord? Yep, the cruise liner speeding past the locks. Clearly they decided to not take the shortcut through Kiel canal.

And now the small ferry is starting to cross. And in the background: The cruise liner!

I realize the earlier pictures in this posts were a lot nicer than these, but look how funny: Above you see the small ferry going around the larger ship, and the wake tracking where it went on its turn. And below, it has turned into a V! Waves are funny.

Interesting pilot ship #wavewatching at Kiel canal

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Some throwback Friday evening wave watching (at the locks at Kiel Holtenau with my friend Sara for a nice and relaxing end of the week) to start the new week. The best!

First: The pilot boat going towards the locks. Unusually visible wake — they are going fast today! Plus an interesting sheltering of waves: The wind is coming towards us so outside of those floating pontoons are a lot larger than the ones on this side that haven’t had enough fetch to build up.

Below we see the same wake: But do you see how it’s just ending on the left? That’s because the pilot boat went in behind the jetty on the far side of the fjord, and it’s only these bits of the wake that were able to propagate outside before the boat went in and the waves don’t make it out of the small channel created by the jetty.

And below the pilot boat going out again in a curve: Love how you see the turbulent wake as well as the deformed V-shaped feathery wake. When you look from the pilot boat down on the picture, do you see the individual “feathers” of the V? Love this perspective on wakes!

And this is what you will see of me when you meet me for a coffee anywhere near water. Sorry Sara, but thanks for the picture! :-)

Wave watching from a train

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You know how they say that the journey is the destination? That was certainly the case for my spontaneous mini-vacation yesterday (and how awesome is it that my #BestTravelBuddy is up for a cross country trip on a day’s notice?). We went all the way from the east coast to the west coast — which in Germany admittedly isn’t that terribly far — to visit the island Sylt in the North Sea for a day.

Even the train ride itself is spectacular, though, at least if you are as easily excited as we are. Wave watching from the bridge across the Kiel canal in Rendsburg (below): A super neat wake of the ship, showing the turbulent wake as well as the feathery V-shaped wake. And as you can see from the rows of foam on the water that are a sign of Langmuir circulation (more about that here): It was pretty windy, too!

But it got even better when we reached the west coast. This is my kind of train ride!

Below is a view of the dam that connects the island Sylt with the main land, and here again you see how windy it is, and this is in the lee of the island. In the lee of those shallow dams you see that it really doesn’t take long for the surface roughness to increase again.

So are you excited to see the wind-ward side of the island now? I’ll post some wave watching from that side soon, but I first have to wade through literally thousands of pictures to cut it down to a handful. I’m already down to about the 100 best, but now I can’t decide which ones to post, because I like them all…

But here is a picture of the train ride back. Do you notice how there are regions with really low surface roughness on either side of the dam, suggesting that this dam is sheltering the water surface from the wind in two directions? Of course it isn’t — it’s just ebb tide and the smooth surface areas towards the right of the dam are wet sand that look similar to a smooth water surface.

So that’s my wave watching from the train! Excited to go back soon! :-)

Wave watching at the locks in Kiel Holtenau

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Yes, we are back to wake watching! Today I went to a new-to-me wave watching spot: The bridge across Kiel canal close to the Holtenau locks, which you see in the background of the picture below. And I should have checked out my favourite ship tracking app for better timing, I had to wait for quite some time before there were any ships apart from the small ferry which you see crossing right at the locks! But the wait was well worth it in the end!

In these pictures, you see very clearly the different parts of the wake. The turbulent wake right behind the ship where the ship has displaced a large volume of water and where the ship’s propeller has induced a lot of turbulence. The turbulent wake is bound by the foam created by the breaking bow waves. And outside of all of this, the V of the feathery wake opens up with the ship at its tip.

I am super excited about these pictures. Do you see the wake reflecting on the right (south) side of the Kiel canal?

And while it was pretty easy to interpret the pictures above, and the one below is still fair game because the turbulent wake of the third ship is still clearly visible, even though the ship is not, it is getting more and more complicated, isn’t it?

But now, with two of the three ships gone, it has suddenly gotten a lot more complicated. And it doesn’t help that the sides of the canal aren’t completely straight which leads to the mess in the lower right corner…

This is definitely a new favourite wave watching spot which you might see more of in the future! This stuff makes me so happy :-)

More wave watching, this time in Kiel

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Beautiful morning arriving back in Kiel… Looking downwind, the weather might seem pleasant (especially when focussing on the sunrise).

But looking upwind however, the wind rows on the water as well as the white caps on the waves indicate that it’s quite windy!

Very cool: the turbulent wake of a ship interrupts the wave field and therefore, with its different surface roughness, is clearly visible!

And below you see so many things: The sand bank running from the lighthouse towards the next headland becomes visible as waves are breaking  on it. The turbulent wake of that blue ship we saw above already is still clearly visible, as is its V-shaped wake. And you see our own wake as the feathery pattern that runs all the way from the bottom edge of the picture to way behind the blue ship!

And here our own wake becomes even more prominent as we turn. Laboe in the background…

Here is another ship, waiting to enter the locks of the Kiel canal. It’s moving only very slowly (so hardly any wake visible), but you see how it’s sheltering the water from the wind so the downwind water appears completely smooth right at the ship!

And here are some more wakes and sheltered spots of water surfaces. Locks of the Kiel canal in the background!

And another look at the locks. Do you notice how the wind rows still indicate that it’s quite windy, but how it’s a lot less windy than it was further out?

And then we are in the Kiel fjord. This is the upwind shore — see how waves are only slowly forming and building up with longer and longer fetch?

And then in the sheltered port a different kind of waves: Our bow propellers mixing the inner Kiel fjord!

Wave watching on Kiel Canal: Bulbous bows and how they shape the wave field

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Even when I fully intend to just go for a Saturday afternoon walk to catch up with a friend, this is what happens…

I get distracted by waves. Like the crisscrossing pattern of waves and their reflections that you see below.

Or the amazing bow waves of ships passing by. Isn’t it fascinating what a huge amount of water is displaced by the ship’s bulbous bow, piling up into a mountain in front of it, then the sharp dip where the actual ship begins? (If you want to read about why ships are built with a bulbous bow, check out this old blogpost).

Having a bulbous bow alone does not always lead to the same bow wave. Which is fairly obvious when you think about it, of course the speed of the ship or the shape of the bow influence the wave field that is created, but also how heavily the ship is loaded, i.e. how deep the bow is in the water.

What you can see very nicely on the sequence of pictures of bows and bow waves in this post are bulbous bows going from fairly far out of the water (above) to fully submerged (towards the end).

And I just love the sharp contrast of the smooth water piling up and then the turbulence and breaking waves right there. Interesting example of subcritical and supercritical speeds, btw: The ship travels faster than the bow wave (so the bow wave can’t overtake the ship, but always stays behind it, forming a two-dimensional Mach cone).

The ship in the picture below is the odd one out in this blogpost: It does not have a bulbous bow but just pushes water in front of it. This is an interesting example of a bow shape that is clearly not optimized for energy efficiency when traveling large distances, but then the purpose of that ship is obviously a different one. But isn’t it amazing how such a small ship creates waves larger than all the other much bigger ships do, just because they have better bow shapes?

But beautiful wakes nonetheless. I love those tiny ripples riding on top of the wakes!

And, of course, the checkerboard pattern of a wave field and its reflection.

Here is another example of a ship with a bulbous bow, this time it is almost submerged. Since they are designed to be fully submerged, this ship is loaded in a way that is closer to what it was made for, and you see that the generated waves are smaller than the ones in the pictures up top.

And look at its wake — really not a lot going on here, especially when compared to the much smaller ship a couple of pictures higher up in this post!

Now for a ship that is hardly creating any waves at all, the mountain of water that it’s pushing in front of its bow looks especially weird since the bulbous bow isn’t visible any more.

See? (And isn’t it cool how the chronological order of pictures in this post just coincided with ships laying deeper and deeper in the water? I love it when stuff like that happens :-D)

And then, of course, I had to include some more pictures of beautiful wakes…

Do you see, comparing the picture above and below, how the first one was taken when the wake had just reached the shore, and the second one the wake was reflected on the shoreline already?

Not many things make me as happy as wave watching :-)

P.S.: Ok, one last bonus picture (non-chronological, we saw it some time during the walk. But that’s ok, I wasn’t going to include it until the post was already done and I decided that you just HAD to see this): Someone who is clearly not using their bulbous bow to their advantage. But at least I get to show you what they look like when they are not in the water. And we got to speculate about how annoying it is to be on a ship with such a strong tilt all day :-D

Wave watching at the Kiel Holtenau locks

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So many people are surprised when I speak of wave watching as of a “real activity”. But to me it is! So I am going to talk you through a couple of minutes I spent looking out on the water where the Kiel Canal meets the Kiel fjord, right outside the locks at Kiel Holtenau.

A light breeze across the fjord

The “light breeze” part is fairly easy to observe: There are ripples on the water, but no actual waves. “Across the fjord” is also fairly obvious if you look at either side of the wave breaker: On the fjord side, there are ripples, on the shore side, there are none (or hardly any), indicating that the wave breaker is sheltering the shore-side from the wind (and dampening out the waves that come across the fjord).

And then: A ship sails into view!

We watch the ship sail past, dreaming of foreign countries and exciting adventures.

A ship leaving a wake

Behind the ship, the water looks very different from what it looks like everywhere else. The wake is turbulent and waves radiate outwards like a V, with the ship always at its tip.

Then, the ship is gone. But we can still see where it went.

There are no waves in the tubulent wake

The ship’s path is completely smooth. No waves have invaded the turbulent waters of the wave just yet, claimed them back. However, the waves the ship created in that V are about to reach the wave breaker.

Also the wind has picked up a little, as evident from the less smooth water surface shore-ward of the wave breakers.

Diffraction at a slit

Right after the waves from the V reach the wave breaker, they reach the opening at the end between the pylons. And what happens now is that the waves get diffracted at a “slit”: they propagate outwards as semi circles, even though the wave fronts were straight when they reached the slit.

How awesome is that? And all of this happening in a matter of minutes!

The weather changes

I said earlier that there was hardly any wind. Later that afternoon, it still wasn’t very windy, but the wind direction had changed: now the smooth and sheltered part has moved to the other side of the wave breakers. There are a lot more waves on the shore side of the wave breaker now, the ones with crests parallel to the wave breaker due to it moving, and the ones with crests perpendicular to it generated by wind. And you see gusts of wind on the sea side of the wave breakers in the different surface roughness.

So if you were wondering, too: That’s the kind of stuff I look at when I am wave watching. And I still find it super fascinating and relaxing at the same time! :-)