I had cut out the hole for the bulkhead inspection hatch, in a oval shape centered on the bulkhead. Subsequently I had seen other builder use two hatches, either side of the mast. However, since I don't intend using the flotation chamber for storage, I'm satisfied that the centered position behind the mast will work fine. I'm working on the assumption that is is only needed for occasional airing of the chamber during off season.
Next was to epoxy and screw on the decks. I also painted on a second coat of clear epoxy on the undersides of the decks before final assembly. The camber on the fore deck was too severe for the 1" screws on their own, so some clamps were needed to pull the deck down tight and then the screws were able to keep it there.
Next step was to make up blocks to clamp on the coaming. There is to my mind a peculiarity in the plans which state to bevel the side deck filler to 15deg and also make the clamping blocks to 15deg, but these block are sited on the foredeck which already has some camber on it, so this results in the coaming flaring out where it sits on top of the foredeck. I'm not sure if this is by design, but I will wait until I trial fit the finished coamings to decide which has the fairest lines.
I made templates from 1/4" ply. The plans call for 11 1/2" wide template, but it turrns out you need wider if you want the coaming to cover the side deck filler. This necessitates a 14" wide board, which would leave quite an amount of waste cutoff. So I decided to glue up a 10" board like so:
Using John Brooks excellent technique which he describes in his Glued Lapstrake Wooden Boats book of running a router bit between the joint off the one guide, I got a very tight joint, so I am hopeful the glueline will be invisible as I used the cutoff from the same end of the board.
Next job is to resaw this board into 4 1/4" boards. The coaming can be either steam bent or made from a laminate of two 1/4" boards, so given that I will have a glue joint in the board, that rules out the steam option.