Nice tip, similar to what we've done if overnighting at
anchor with our dog. During the first daylight dog run to the beach in the
dinghy, I look for a long driftwood branch or board and drive it into the sand, just above the high water
line.
The upright can be easily spotted at night with a flashlight and serves the same purpose as the driveway markers. Not as reflective, but is natural and can be left in place for the next dog owners.