Can a low flying but super fast jet spray water from the surface of the ocean?

I've seen this visual effect done many times in movies. It's often done to highlight supersonic speed just a few feet above the water.

Do the laws of physics even come close to this being plausible?

Bonus: Can you provide photograph evidence of this happening?

enter image description here

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    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$ – Farhan May 9 '17 at 14:21

The visual effect in the picture you found seems to suck water out of the sea, in this real footage the f-18 air shockwave tends to push water down, and makes a trail.

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    $\begingroup$ This related video has a bit more "splashy" effect. But wow that's incredible - they're flying what, 10-20' off the water? That's crazy! $\endgroup$ – Wayne Werner Apr 24 '17 at 15:23
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    $\begingroup$ I suspect that the cloud at the level of the airplane in that video isn't water that has been kicked up, but is rather the vapor cone from the air. There's definitely a trail on the water, but it's relatively small compared to the (CGI) picture in the OP. $\endgroup$ – Michael Seifert Apr 24 '17 at 15:29
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    $\begingroup$ ... am I the only one who's concerned that an F-18 buzzed a waterway that obviously had lots of boats and stuff, at such low altitude? Is that not as dangerous as it looks? $\endgroup$ – yshavit Apr 24 '17 at 16:08
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    $\begingroup$ @yshavit It's the Blue Angels. If it doesn't look dangerous, they don't bother doing it! $\endgroup$ – Cort Ammon Apr 24 '17 at 18:52
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    $\begingroup$ @yshavit It's hard to judge how far the aircraft was from any of the boats. The video seems to have been shot from somewhere near Fort Mason, with the curved structure at the end being Aquatic Park Pier. (The two-humped hill on the horizon at the start looks like the north side of the Golden Gate Bridge, too.) The Golden Gate is more than a mile wide and Alcatraz is about a mile offshore, so the plane was probably at least half a mile offshore, but filmed with a telephoto lens that makes perspective hard to judge. $\endgroup$ – David Richerby Apr 24 '17 at 18:58

And this video gives quite the explanation on how this happens...

The way it works:

condensation effects:

  • the air speed increases as the air flows around the aircraft
  • this can mean, that the air may travel faster than the speed of sound
  • air pressure and temperature drop, when the airspeed increases
  • this leads to condensation, because the cold air cannot hold the amount of water anymore
  • the cloud the aircraft is seemingly dragging along are condensation effects
  • the cloud is a local effect, it is not dragged along

shock waves:

  • they are created, when the air cannot get out of the way of the aircraft fast enough
  • this way, they form a pressure wave
  • that is the sound the aircraft makes
  • generally two waves, one bow and one tail

the rocket at the end:

  • the air is cold
  • there are tiny ice crystals in the clouds
  • they make the two pressure waves of the rocket visible
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    $\begingroup$ The best is the visual shockwave at the launch of an atlas rocket at the end of the video!!! $\endgroup$ – mike Apr 24 '17 at 15:28
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    $\begingroup$ Please "bring the content here" by providing an explanation in the answer. $\endgroup$ – Lightness Races in Orbit Apr 24 '17 at 17:11
  • $\begingroup$ This answer, while detailed, does not actually answer the question. Do real airplanes create such fumes as in the rendered image from the OP, or do they not? $\endgroup$ – AnoE Apr 25 '17 at 8:49
  • $\begingroup$ To quote my comment from the other answer: "The vapor cone is generated from the pressure wave of the aircraft, same as the trail on the water." $\endgroup$ – mike Apr 25 '17 at 9:00

I've wondered about this, too. From what I've discovered looking around online (and I am NOT a pilot or physicist) is that it's something of a myth -- at least in terms of the dramatic waterspout-effect like in the painting above and countless movies.

A fast, low-flying jet may create some shockwaves (not to be confused with the "vapor cone") that would disturb the surface of water, or some updraft that sucks up spray, but nowhere near the massive amount of water depicted.

The idea may have started because of images like below, where a Blue Angle flies low over water then, as it pulls up, the jet engines directly angled toward the water do indeed blast a huge spray -- but that's very different than sucking up water in level flight.

So, the answer is: yes, a low-flying jet can disturb the surface of water, but not quite in the way it's depicted in the movies.



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