Starboard would be a bit heavy for companionway hatchboards in any case - and too pricey.
Standard Acrylic or Lexan (let cost be your guide) works well, and lets light in too. If you want the privacy you can get coloured acrylics, remember that even heavily "smoked" plexi is transparent when there's more light inside.
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"