In 2014 I picked up this gorgeous gal from my friend Brian Gundy. She is my only boa and easily my largest snake. I dig her! Mellow, easy going and just gorgeous. She is in a 48" x 24" by 18" AP vivarium with a shelf. She used the shelf a lot when she was smaller but now that she is a full sized gal she seldom does more that drape her head on it.
I wanted a a jungle looking vivarium for her but I found she seemed to shove everything into a corner. So now she is on coconut husk with a couple of hides and a couple of cool rocks for cover. That seems to make her happy and honestly, its easier to clean.
Cool fact for people not familiar with Boas, they have a squarish/rectangle body shape rather than the round or oval shape of a python. In the photo below you can see the "flat" side. I'm feeding her rats, and she would easily overeat if I let her.