Wave marks on the shore

Image from i.redditmedia.com and submitted by cyan1618
image showing Wave marks on the shore

mikerockitjones on June 17th, 2018 at 13:46 UTC »

The giant slug has left its trail.

NightWillReign on June 17th, 2018 at 13:46 UTC »

What’s that blue stuff right next to the trees?

AchuAjith on June 17th, 2018 at 14:13 UTC »

Is that a sine wave?