Although the 5.7M SibLim thread is the apt one for my following suggestions, there could be some value WRT the 7M version... where building is done in the way of filleting, glass taping, and also epoxy painting the interior, whilst still in the early stages of exterior sheeting.

It should work out to be flipping modules, so that access is possible to all corners, while standing with feet on the workshop floor.

At 2M beam, 1/2 beam distance is reachable(with my average length arm as a distance quage), and when one or other of the halves is theoretically flipped to face inside upwards.

Joining the halves on the centreline, should make the flat workshop floor a convenient flat building bed, on which to  lay the bulkheads and frames-- with the CL horizontal and the waterline vertical.

The topside planking/strake, is bent over and onto(the bulkhead frame structure), as the first sheeting step, with the  chine and the deck/sheer lines being the guides to a fair lay of the panels.....perhaps I do not fully appreciate the details of pre-cut panel construction, but surely accurately cut panels wired together along their edges, should produce a fair curve?

Stringers and battens strategically placed between the chine will then help to support a fair assembly.

I would like to see a template panel of the arched deck, used as an assembly aid, and possibly with a small log on the inside edge of this deck template/panel. This, as well as the chine, should create the coreect and fair shape shape?.

Surely a chine log would not be needed, and double bias taping inside and out would be all that is needed, to create a stiff enough hull piece, that can flipped over for working the inside?

Gary wrote:

Now while I feel there is still some to learn about the final skinning of this vessel, it probably won't be learned other than at full scale. I am also mindful that David Tyler is a scarce resource (only one of him in the whole world apparently) and I would not want to think about him contemplating how many puzzle joints can dance on the head of a pin when he could be working on his new improved soft wingsail or answering the loads of other interesting queries that come his way.  

I did the rough fairing of the chine logs on Annie's Fánshì (as we must now learn to call her) using an electric plane. It took quite a while, and I made buckets and buckets of shavings. On the model, there's less physical work, but it's harder to work accurately. I'd like to get away from that, but retain the fairness of having solid timber there. So I went back to the Gougeon Bros and looked at their stringer-on-frame method. They put 1 1/2in x 3/4in stringers on edge, to get the maximum stiffness, and therefore fairness, using the least material. I think we can do that here:

https://www.westsystem.com/the-gougeon-brothers-on-boat-construction/

I agree with David on Topsides first, and I particularly liked his idea of "hangers" incorporated in the frames from which to hang them. that should ease their installation dramatically. Once hung they will sit patiently awaiting wire or cable ties or whatever. 

I am curious about why Jeremy is happier with a timber mast than an alloy one. I _think_ I read recently that Michael Storer says the performance of a box section mast is better than a birdsmouth and lighter than alu. (hope I am not misquoting him). He does mostly do dinghies however. Then again C-Tech in In-Zud seem to be offering almost affordable rices for carbon: http://www.carbon-tube.com/index.php 

Really don't know about butt joining the bottom a piece at a time. I would have thought that it would be easier to get a fair twist with a contiguous piece of ply, but if the butt joints landed on something substantial with a good deal of overlap its not going to be a big deal to do and the outside is glassed anyway so for sure there is more leeway. 

On the topic of cleanup and clamping being required for puzzle and scarf joints then its hard to see it being terribly different amounts of work, and having just built all my kitchen worktops from 45mm wide hardboard planks I can attest to the prowess of the Makita BO6050J which will make cleaning up anything fairly trivial. So I am still inclined to use puzzle joints where applicable.

Now while I feel there is still some to learn about the final skinning of this vessel, it probably won't be learned other than at full scale. I am also mindful that David Tyler is a scarce resource (only one of him in the whole world apparently) and I would not want to think about him contemplating how many puzzle joints can dance on the head of a pin when he could be working on his new improved soft wingsail or answering the loads of other interesting queries that come his way.  

Jeremy wrote:

Seven metres length and 2.5M beam is more than my garage space will allow, but I have just heard that David has a 6M design as well ...

David wrote:

Len wrote: As an exercise in thought, I would be inclined to assemble the hull panels ahead of time and apply in one piece as giving the fairest curves unless I was doing two layers in which case the second layer could act as a butt block and I would install piece at a time.

Fair curves are still possible with the panels added in pieces. But thin plywood doesn't lay in a fair curve over frames alone. There's nothing that identifies an amateur-built boat more than wobbly chines, and although it's easy enough to adjust them in a dinghy before filleting, it's harder in this size of boat.