In article . com,
says...
We have an acrylic bathtub that my wife uses every day. At our
previous place we had a 'soaking' tub that my wife loved.

The problem is that the new tub is too long and the back rest is too
steep for her comfort. She is always sliding down as she bathes.


I can think of a few ideas to modify the tub. .....

Water proof pillows or cushions?