I've tackled the deadlights. I found out portholes that don't open are deadlights.
The opening is around 6 inches. I'm using scrap 9 mm ply. After rough cutting on the bandsaw I used a table saw jig to get a perfect circle. Since they are very visible this needs to be quite accurately cut.
I had never cut a circle with the table saw but it turned out to work really well. I don't think I needed to use the band saw at all to rough cut the shape. I could have used the sled to just gradually cut the corners till I had a circle.
I used the circle cutter to do the inside. This is a photo of the circle cutter when I did the hatch liners.
I had picked up this rabetting bit in the cheap bin at one of the wood shows and it's paid for itself many times over.
It cut a nice 3/8 th rabbet just a little deeper than the thickness of the acrylic I have.
I made a pattern and marked it on the plastic. It comes with a coating on both sides so it does not get scratched. The plastic does not cut terribly well and tends to chip a bit even with a very fine blade. I sanded the edge and called it good enough.