These plexiglass bubbles were often used on multihulls, "back in the day" when we all had to build our own boat to get one. This bubble was on my previous SeaClipper 28, 23 years ago... It was from Curd Enterprises in Charlston SC. (Don't know if they still exist)
The side wall and flange thickness was only 1/4", thinner on top. For this reason, and for shade, I made a "cap" for mine, out of flexible polypropylene fabric
. (Glass on the bias would work too.) I stretched Saran Wrap over the bubble first, and used it as a mold
. Then sanded out the stuck Saran Wrap, from inside the cap, and glued it into place with clear silicone. After this, you could stand or fall on it without worry.
I used to stand watch from inside this 32" bubble. It was a hoot! If you use ArmorAll on it, it fills scratches, turns more clear, and repels rain.
I may do it again on our Delphys, (But smaller). I have seen them available by Googling plastic "bubbles", "observation domes", or "hemispheres"... They are often used to hide the TV cameras on the ceiling in WalMart, etc. There was never a "marine" version, except very small, in Lexan
, 30 years + ago...
Go for it!