Pieces of cedar were used to add width and length to the section of cabin roof that had been cut out. This forms the hatch. The fore-aft edges of the hatch were rounded over by first planing and then sanding .
 
Also in this picture the guides that hold the storm boards in the cabin rear have been fitted. These have a groove routed in them for the storm boards to slide down.
 
I cut a piece of maple to glue to the front of the hatch opening. This extends 15mm above the cabin roof and should stop water blowing along the roof and into the cabin. The front edge of the hatch also extends down to cover this timber. The only drawback I see with this is that the hatches need to be installed from the front of the runners.

Finally cut out ! Looking a bit rough but a rasp and sanding  soon tidied this up. At least now I didn't have to climb through the hole to get into the cabin.

Just checking with Marg that I am following the line on the inside as well as the outside.

Next job was to cut out the hatch openings. Using the previously drilled holes I drilled upwards through the cabin roof and marked the hatch position. Then using a jigsaw I tried to carefully cut out the hatch. Marg was inside the cabin to provide support when the cuts were finally done.
 
This was not a comfortable postion to work in as I had to push up on the tarp roof and concentrate on the cut.

Cabin roof on ready to be filed and sanded back to cabin sides and front.

Here you can see the double noggin and cross beam that will allow the hatch to be cut out once the cabin top is in place. Make sure to drill some holes down through the liner between the timbers so that you don't lose the position.
 
Once all the timbers had been faired I gave the timbers and the top of the cabin liner a coating of epoxy and preservative treatment. The underside of the cabin roof was also treated before gluing and screwing down onto the beams.

I finished the roof beams and noggins. At this point I also ran some electrical wiring for the internal lights and navigation lights on the front sides of the cabin. I glued blocks of cedar to the cabin liner and ran the wires down through holes in the blocks. A good dollop of epoxy filler worked into the hole after placing the wire sealed the cabin roof.

As we needed to get access to the back yard so that shed extensions could be carried out we moved the boat out of the carport and under a "temporary garage". This steel frame and polytarp structure was just big enough to cover the boat and, although not totally waterproof, at least provided protection from the sun and light showers. (Doesn't really rain often in the Burdekin but when it does it can really pour). Working on the roof, up close to the tarp, was hot and sweaty.

Cabin Top and Hatches