It appears to be something of a known length that shows up well in photos, probably the excavator uses it all the time.
https://archaeology.org/wp-content/uploads/2025/08/News-20250821-Hippos-Mosaic-1.jpg
Like I said, we all use them. I am a Geologist on Excavations, so I had my own. I haven’t been on an active one in years, but would love to do it again.
