I like your sketches!

DIED has a crescent shaped structure (similar to the third sketch but without the bottom opposing crescent). When the water level is right (our water levels very drastically from season to season) this structure is a great fishing spot.

JHAP
~~~~~~~~~~
"My mind is a raging torrent, flooded with rivulets of thought cascading into a waterfall of creative alternatives."
...Hedley Lamarr (that's Hedley not Hedy)