Agree. It's likely too big for 1/2" - at least not without reinforcement. 3/4" should also be easy to find.If you can use the existing as a template, you should be ok. Maybe look for some thicker starboard as the material isn't great structurally. I used some 5/8" material and thought it was pretty decent.
Sorry I mis-understood what you are using starboard for. Should work fine. I have used Starboard to replace a few melamine panels that got water damaged. Came out great.Don't use Starboard. It's not structural and doesn't adhere with epoxy. Use Coosa board or marine plywood and glass it in. Done right done once!
I'll get some tomorrow when I'm down working on the boat.If you can post some more pics from various angles, that would help.
Have you thought about just repairing the existing one and painting it? Got some pics of the condition?
Probably will end up replacing the vertical pieces with starboard. Would be nice to replace the horizontal piece as well with starboard and be able to retain some rod holders.Man, what a shame. That's poor build quality - lot's of voids and such. That's definitely worse than I was imaging and, while not particularly "hard" to fix, it will be quite labor intensive.
So... what do you "need" or "want" a new door to be? Do you want the rod holders? Would you be happy if the new door was just a simple, flat door? You could always build a box near the top of the door to house rod holders. You could even make the box removable with thru-bolts or even wing nuts. I'm just thinking out loud there - but you get the idea... it doesn't necessarily HAVE to be done to match the existing setup.