Sleeping with Rear End Up

Hi Steve (and everyone else),
I hope you're all well and enjoying your time with your turtles!
You might recall that we have an older, female RES turtle, Turtleneck, living with us. She's almost 30 years old, and she's actually my housemate's turtle, officially, but I look after her much of the time. The past couple of months, she began sleeping (in the water) with her rear end elevated a few inches -- I've begun to wonder if turtles have some kind of ballast, and if so, that she's "lost" her ballast? (or something similar) ... Do you have any insights into this, Steve? Thank you very much!
I hope you're all well and enjoying your time with your turtles!
You might recall that we have an older, female RES turtle, Turtleneck, living with us. She's almost 30 years old, and she's actually my housemate's turtle, officially, but I look after her much of the time. The past couple of months, she began sleeping (in the water) with her rear end elevated a few inches -- I've begun to wonder if turtles have some kind of ballast, and if so, that she's "lost" her ballast? (or something similar) ... Do you have any insights into this, Steve? Thank you very much!
