I have seen similar effects over the Chesapeake Bay in Summer when haze is particularly bad. I believe that effect may have contributed to the crash of JFK, Jr. several years ago. He was not instrument rated, and the weather at the time was similar to the conditions I mention. Technically, it is visual flight rules (VFR), but in reality someone who is not instrument rated could get very confused.
I have seen variations of that effect in the offing of the River Plate (Río de la Plata), in nightime near the Scilly islands (very disturbing) and out of Golfo San Jorge in our litoral.