Don't give up James, I know about builds taking forever, my Chaconia is also under construction for several years now. If weather isn't good, it's not really encouraging, I know that feeling too. But try to concentrate on bits and pieces that don't require the hull to be finished and finish those off during winter time. After the hull is finished or nearly finished, you won't feel much to build those anymore since the resulting hull gives a certain feeling of satisfaction already

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I'm watching this since the subject really is interesting and quite rare! Hope to see some progress from time to time. Details are in fact the most hard to build!
For my rounded sides on the deck edge on Chaconia I used a half circular piece of wood, cut it in two and mounted it on top of the frames. It also gave an edge for a removable part of the main deck. I aftwards integrated it in the hull with fibreglassing and did a tiny layer of car body filler over it. Honestly that wasn't the best idea, as when you start sanding the filler, it has the tendency to peel off once it's too thin. Not sure how to solve it. Hope you have a good solution for it so that perhaps I can use it in a next build!