I believe pressed PVC board . We use it for boat seats and there are different levels of density and quality . Sintra is one name brand that is high quality . Check with local plastics supplier.
I have one and it's a starboard hard plastic or similar material. I can take some close-up pics of my stand if you like, I love it and hope I can find something like it for other boats in the future.
brian Neumann
Sorry I didn’t see your response until now. I can take some close ups & multi angle pictures of it and post them in the evening. Keep us updated on your project, and if you need additional pics or measurements .
Brian Neumann
The company was actually JRS Innovations and I believe he has stopped producing products for now. The last I talked with him late last year he said he might start up again. He work was amazing! The material is called Expanded PVC. Starboard is a more dense version of expanded PVC, more expensive and much heavier but is designed specifically for marine applications.
JRS Innovations stand for my JAE 12 Rigger. Really like the stand & hope JRS makes them in the future. Strong, fuel/wear-proof, supports both boom tubes, rear tub plus the ski. Took way more pics than needed, just wanted to show the design/details if your trying to build your own. Hope these help!
Brian Neumann
They are very Nice I know I am Late to the horse race BUT. . . . . If anyone has one o the Thunderboat stands (SLR) or Lauderback (Blazer) Stand. Some pics with mesuerments would be Kewl. .