Yesterday I was flying above the Mediterranean sea, it was a nice day, without storms or strong winds. I fly around 20 minutes above it before arriving to the ground.

During these 20 minutes I saw that the sea had plenty of white spots, some of them really big, more than a ship. They were not changing size, changing shape or disappearing as waves would do. Really, each one of them did not change at all during the minutes I could see them.

It looks as foam from a chemical product or something similar. But there was A LOT of spots during long time in the whole sea, as far as I could see and during the whole travel. Close to the shore, the white spots disappear. What can that be? If is some chemical, where does it come from? Waves? I dont think so...

-I am not sure if I should ask this here-

See this photo I did. They seem at the beginning waves but they would change. These spots in the photo didn't change at all

enter image description here

I was flight through more or less this route:

enter image description here

  • 2
    These are waves cresting over the ocean, when you fly they are less obvious as you're much higher, but choppy surfaces causes the waves to crest. Out in the ocean the water does not necessarily move as much as you'd expect and can stay 'in place'
    – Aravona
    Commented Oct 30, 2017 at 12:11
  • 1
    Yeah I know that the movement thing is not clear. The main problem is that the white spot didnt dissapear. When a wave goes up makes this foam and then goes down and the foam dissapear. These spots didnt dissapear during minutes long (I didnt see any dissapear, they didnt change size or shape)
    – Ivan
    Commented Oct 30, 2017 at 13:24
  • 1
    They do not disappear in a short timeframe, Ivan. This is normal.
    – Rory Alsop
    Commented Nov 1, 2017 at 11:19
  • @RoryAlsop but they dont stay for minutes long (I saw them for more than 3 minutes until I lose sight because of the plane). Any wave crest last so long
    – Ivan
    Commented Nov 2, 2017 at 16:29
  • 2
    Yes they do. I grew up flying over the sea every day. They can last for way longer than that. They aren't wave crests - they are what is left after the wave crests. Out at sea it doesn't go when the wave vanishes. The next wave catches it and can add to it
    – Rory Alsop
    Commented Nov 2, 2017 at 19:43

1 Answer 1


They are wave crests. It's wind folding over the top of waves, which mixes them with air. They're also called white caps. If they're closer to the shore you have a change of water color to a lighter blue. That lighter blue could mean there's coral below or a shallow bottom. Waves do not move fast. They're more like a drum in the water slowly rolling forward, with the wind picking up the back side & folding it over the drum.

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Rory Alsop
    Commented Nov 1, 2017 at 11:18

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