McMaster-Carr sells G10, I bought a sheet to use for backing plates for thru hulls. I can’t speak to the price point versus Defender but I recommend shopping around. An industrial supplier might be cheaper than a marine supplier.
G10 is not that hard to cut I used a Sabre saw to make circles, but it was really tough to shape it to the curve of the hull.
G10 is not that hard to cut I used a Sabre saw to make circles, but it was really tough to shape it to the curve of the hull.