I don't have google earth, and I don't know how to get coordinates from google maps, but...
go to google maps and type in "
dos estrellas mexico"
go into satellite view, and
zoom in on the closest lake to Tulum
Look at this lake at close range.
strange and very similar to the caribbean site.
I've looked at all the other lakes nearby, and they do not have the same anomalies at all
P.S. the reason I didn't suggest searching for "Tulum mexico" is because it ends up showing tons of locations in a whole bunch of different places - hotels etc.