[Ken Maltby]

Or you could make a waterproof see through case from plastic window glass replacement sheets, like from Home Depot or Lowes. You would build it up with top and bottom sheets, sandwiching a sheet that has its center cut out to match your reader. You could use a Dremel Tool to create a groove for a rubber "O" Ring, to go between the center sheet and the bottom sheet. The top and middle sheets would be glued together and the bottom sheet would be tightly secured to that assembly, by a number of nuts and bolts.

You would need to remove the device to charge it (you could use a Qi microUSB adapter, to charge it in the case) or to set the document/book up. [I seem to remember a post where someone had the magnetic switch event set to turn the page.]

I wouldn't try it below 66' (2 atmospheres), but you could probably read at the bottom of your pool.

Luck;
Ken

If you just wanted it for the bath/rain and weren't taking it diving, you could get a sample rubber sheet and cut that to match the middle plastic sheet and not need the "O" Ring.

Hmm... I wonder if you could have a magnetic bit, that you could have inside the case, and maneuver over the touch screen, to make selections?