Tag Archives: ship

Spotting both the V-shaped and turbulent wake of a faraway ship on a calm day

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The title says it all, I guess ;-)

In the picture above, you can still see the ship on the left, and having seen the ship, I am sure you can recognise the turbulent wake in the picture below, too: It’s the lighter blue stripe towards the horizon with darker, rougher sea surface to either side.

And in the top picture, you see individual “feathers”, i.e. parts of the V-shaped wake with the ship at its tip, coming towards us, whereas in the bottom picture, a little later, the one part of the V has reached us and we see the “feathers” as the wave crests that are more or less perpendicular to the bottom of the picture.

I find it interesting how the perspective makes it seem as if the wavelength gets a lot longer towards us, but that’s really only the perspective. Also the closest two or so crests are really hard to see — can you spot them? The closest one you can see better on the right side of the picture where there is a sudden change from a darker to a lighter part coming across, and the second one you see more easily on the left side, again, with a quick change between darker and lighter. And the third one is fairly easily visible all across the picture.

Do you do wave watching when you are at the water?

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

Sightseeing in Berlin? Any excuse for a #wavewatching trip!

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Berlin is full of interesting history to discover … for example that of ships that have gone past on the Spree! :-D

Let’s start with some easy wave watching. In the picture above, you see a ship and its wake (both parts: the turbulent one where the ship has gone, and the feathery wake that forms the V with the ship at its tip). And you can make out the wake of a ship that has already gone round that bend of the Spree: the turbulent part showing a different surface roughness, and reflected remains of the feathery V on the right shore of the Spree. So far, so good!

Below, you see two turbulent wakes: The one of the ship you still see, and then the one of a ship that went the other way, but already went out of the area captured in the picture.

Berlin Cathedral Church seen from across the Spree

And here is a series where you see the feathery wake reach the side of the Spree…

Bode museum and television tower Berlin

…get reflected there…

…and then meet the reflection of the other side of the V to form a checkerboard pattern! Would you have known what’s going on here if you hadn’t spotted the ship just about to leave the picture, or seen the previous images?

Below is another nice one. What happened here? A ship sat there, waiting, and then started moving again right before I took the picture! This is the beginning of a turbulent wake right here.

Reichstag, home of parlament

And below another nice wake plus reflection.

And here you see another feathery wake, plus the turbulent wake of the same ship on the other side of the Spree.

Reichstag, home of parlament

Similar picture as above, except in a different spot…

German Chanellery in Berlin seen across the Spree

Yes, that’s a pretty good representation of what sightseeing trips with me are like ;-)

Long-distance wave watching during sunset

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Have you ever noticed how much you can observe when you look at water from a distance? For example in these pictures, you see the tracks of ships that are long out of sight! Do you see the circle that one obviously drove before leaving our field of view?

For the ships far out in the fjord, you can’t actually see the waves so much as the turbulence they created that left the surface smoother, thus better reflecting the light from the low sun (and appearing yellow-ish). And how cool how you see how newer tracks run over older ones! Only for the ferry in the bottom left you can actually see the waves themselves.

In the picture below we actually see the waves that both ferries made.

Zooming in: How cool does it look to have these waves almost all the way across the water? And do you see how they are bound by the ship’s V-shaped, feathery wake? I find it really fascinating that there are such large surface elevations, but only inside of the ship’s wake.

I just love wave watching, even when I am not even that close to the water :-)

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!

Sunset wave watching in Gothenburg. Wakes under different light conditions!

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Wave watching from high up gives you a whole new perspective on wakes, and depending on the lighting, features in the wave field become more prominent or fade away.

See for example below the ferry: You very prominently see the turbulent wake right behind the ship, and you see the waves of the wake opening up in a V-shape.

Above, there is still a lot of ambient light from the sky. Below though, the same ferry, similar spot, 30 minutes later: The turbulence is a lot harder to see since colors fade away, but the V-shaped wake becomes really clear since one slope of the waves reflects the city’s lights while the other reflects the darkness.

Another ferry coming in, another wake… Below the surface roughness becomes clearly visible with the turbulent wake right behind the ferry and the bow waves fanning out.

That was one brilliant mini cruise! Thanks for joining me, Frauke, and for staying out on deck with me — despite the freezing temperatures — until we were far out of the port and the light was gone completely. The sacrifices we bring in order to wave watch… ;-)

Refraction of light in ship exhausts

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Leaving the port of Gothenburg after our mini cruise, A and I obviously had to secure the prime spot for wake watching because I wanted to check out more of the weirdness I talked about in the last blog post. So while we were waiting for the ship to sail, we had the best view of the ship exhausts, too, and it looks really fascinating:

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Do you see how the hot exhausts have a very different refraction index than the cold air around it?

Stena Germanica is the first ferry that size running on methanol (super interesting, btw, how the company is exploring new technologies!) so the exhausts are mostly clear.

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Although on occasion it does still look a little more like what you’d probably expect of a ship’s engine:

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But nowhere near as bad as it used to be! Can you imagine that this is what all ships looked like not so long ago?

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Good thing there are tons of regulations in place nowadays, and companies like Stena testing out new technologies.

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Can you imagine what Kiel would look like if there was more than one ship making that kind of smoke?

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Wakes and what they do to the sun’s reflection

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When I said that wake watching made me happy last week, did you really think those were all the wakes I was going to show you? Ha! No, I have plenty more! :-)

Today, I want to show you a couple that have one thing in common: the way that they show up against the sun’s reflection and thus become a lot more visible than they would be if they were just reflecting a uniformly blue or grey sky.

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Reflected wake

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The best ship-watching of the year happens during Kiel Week (even if I do a fair bit of ship-watching year round ;-))

But this year, I was absolutely fascinated with wake-watching. Look at the sailing ship below and its beautiful wake!

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You very clearly see the streak directly behind the boat, caused by turbulence where the hull pushed through the water. And then there is the actual wake, fanning out from the ship.

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And then that wake gets reflected on a sea wall as the ship is sailing past!

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Watching things like this makes me happy :-)