Oh Boy do I feel all your pain!!! I have a hard time sitting in the low beach chairs at CC. I do have a trick/hack though......I dig a hole about eight inches deep with my feet (or you can bring a sand shovel) and about 8-10 inches wide, enough space so my feet are flat in the hole . Putting your feet in the hole and pushing off the arm rests makes it so much easier to stand up. That and rocking forward......1, 2, 3 UP!! Then I just step up and out of the hole.
MJ