In our case, this version of cutting in the boards is not suitable. It will appear only in the 19th century. In the 18th century, the "lost boards" method was used, as shown in the drawing in message 65.
If we talk about your method of cutting, then you are absolutely right, the use of margin plank before waterway is mandatory. But this is on decks. On superstructures, the waterway did not rise above the deck flooring, but was flush with it. Therefore, margin plank was not used there.
Thanks Iutar. I am a still little confused, but that is nothing new for me. Goodwin shows waterways as below and they all have a rise to them rather than being flat so there would be an edge area as I show on the drawings above if a cut into the water way is made.
Allan
Mark, you will have another discrepancy: the semicircular turrets are toilets for midshipmen, they should protrude slightly beyond the edge of the hull.
These towers are called roundhouses.
Hi Allan,
Regarding ..... "still question the opening for the sprit through the deck"......
I glued everything together exactly to the millimeter, as shown on the drawings. See the attached assembly drawings, where this is further emphasized regarding the sprit. Could you please give me more details about what is wrong? Thx
Iutar,
Allan and myself contacted the Ship Yard who build 2 centuries ago the Agamemnon.
They responded as follows (extraction of the mail):
So we downloaded a lot of plans and one is indeed showing the toilets for midshipmen.
However they are not shown on all drawings of the Ardent Class.. However I will add them....after the second planking...
I totally understand your dilemma. I think part of the problem is that the kit drawing is not faithful to the contemporary drawing. For example, they forgot to continue the upper gun deck under the beakhead bulkhead and end at the stem. Compare the contemporary plans with the kit drawing below. Assuming the forward most bulkhead on the kit drawing, #1 forms the beakhead bulkhead, they have it in the wrong place which adds to the problem. The beakhead bulkhead is about 4' 4" aft of the inboard edge of the top of the stem. The kit plans have it 6' 2" aft. If this bulkhead was farther forward as on the actual ship, the opening for the sprit would be partially forward of the beakhead bulkhead and partially aft of it. I added some lines on the drawing below to compare. Also, consider Iutar's post that there is no platform above the beakhead portion of the upper gun deck. I am convinced he is correct that there is no part like #59/21 as there would only be about 25 inches between the upper gun deck at the beakhead and part 59/21. If you follow the contemporary drawings though, it may cause other problems with the kit assembly. I apologize if I have made this even more confusing. I did add where the beakhead bulkhead would be assuming the RMG drawing is correct.
Allan
The first quarterdeck beam is more complex. It is also wider and thicker than the other beams, it is also visible to the viewer and has a groove for cutting in the deck planks. But rather large bridges are attached to it on the sides, which also have a border of bare beams along the edges.
Here, too, the model designer Chris made some kind of base for the fence, but there is no need to do it.
At the poop-deck, everything is the same: the first and last beams are wider and thicker than the other beams, they are thicker than the other beams by the height of the deck flooring, have a groove for cutting in the deck flooring boards, are not covered by boards themselves and are clearly visible to the viewer.
Mark, pay attention. In these and other photos, you can clearly see that the deck planks taper to follow the shape of the hull. That's why there are so few "lost planks." The planks were made of softwood, they were long, straight, and tapered smoothly. They were not the same width along their entire length. This is also clearly visible in the drawings from message 65.
Hi Iutar,
The drawings are at RMG and can also be found on the Wikicommons site. They have the orlop, lower GD, upper GD, and quarter deck in plan view. The only view of the poop deck is in the inboard profile plan.
Goodwin shows waterways as below and they all have a rise to them rather than being flat so there would be an edge area as I show on the drawings above if a cut into the water way is made. 
