Too bad some enterprising soul cant take a hike back there and see the survey lines that were surely done prior to any purchase- if they haven't been removed.
A point of interest though is that the photo is taken from an angle and many tall trees may look like the waters edge but the actual edge is closer to the water that it may appear.
Seems like enough distance though that the line is NOT in the water- IMHO- in many places. When looking at the photo from above on my place not too far from there the same thing happens with by farther line and tree height.
There is a real estate site that shows survey lines very accurately throughout the area when getting the proper height on the satellite photos-at least mine and my neighbors are exact and right to the trees where the survey tape is located. ya gotta zoom in and out a bit to get it to show- darned if I can find it tonight but when I do will post it up.