Wow -- thanks for posting these. Interesting to see the footprint of the long boat. When I first came across it (my reel snagged on something when we were doing a big circle around the anchor line), I silted the area up pretty quickly, and then tried to measure it using my body length.
You can see the offending reel line draped over the boat and looped around the bow. Then I go back to find my buddy and lure him back to show what the line was caught on.
https://www.youtube.com/watch?v=1spNkIGCbYU