Thursday, November 09, 2006

How we got here from there - Part II

'Part I' hit on what possessed the decision to choose a proa. Here I'll touch on why a Harry-style Visionarry proa.

For a detailed description between the four proa types, refer to Cruising Proa Concepts

We made the decision for five reasons:

1. The idea of having the accomodations separate from the sailing loads made sense to us since it maximizes the accommodation space without having structural members and a mast in the middle of the salon. Additionally, having the living accomodations in the weather hull maximizes the righting moment.

2. There are several other Visionarry's either in production or sailing. Not sure what the count is but it seems like there are three Visionarry's on the water and several other builds in various states of completion.

3. I like the lines. There's something to be said for the sailing performance of a boat being proportional to the beauty of her lines. I think these lines are lovely..

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4. The guys at Harryproa are on their game. Rob (Designer) has been answering 100's of questions for the past year and Mark (builder / draftsman) has been gracefully answering boatbuilding questions during the past month or so. This doesn't feel like a one night stand. They are passionate about their proas. I'm very clear about being an amateur boatbuilder and having them there for back-up is a good thing.

5. Plans are in good order. Being an amateur at this I didn't want to rely on years of experience to determine the best lay-up schedule. The plans I've received to date had about the right amount of detail. Additionally, cutting files are available. A few of the designers I spoke with regarding cats wanted to double the cost of the plans if .dxf's were included for CNC routing. This blew my mind since the cost of a .dxf must be significantly less than a full size print. The concern was that I would use the .dxf's (2D files) to reverse engineer their boat. A bit of paranoia out there perhaps. Perhaps there's more to this.

That's why we chose a Harryproa. Mercifully Rob has written a lengthy bit about the world of proas through a designers eyes. Check out his article on proas.

Are there things about building a proa that make us nervous. ABSOLUTELY. With any design there are concerns. With this even more. Specifically, the design does not have hundreds of thouands of sea miles under her bottom. Two of our criteria were "Robust Design" and "Ability to ride out a gale with ease." Neither of these have yet been proven. We felt pretty good about the boats ability to ride out a gale since if I were to choose any type of platform to heave to in or lie-bare hulled in it would be square raft 1/2 mile on each side. The profile of a proa fits this pretty well. I imagine getting her lined up with a drogue or an anchor might be tricky but once there I can't imagine a more comfortable platform. Adding to idea of a raft is the ability to lift the proas rudders taking away her "tripping point".

This leaves robustness. My biggest concern to date is the mounting of the rudders. It's a bit of a complex problem with a design that needs to allows the rudders to rotate through 270 degrees, lift in the Z-axis and rotate about a pivot point in the event something is struck. This just seems to be an area that will become robust from some hard knocks (ocean passages) and clever design. Perhaps the design is there already, but we'll have to wait and see.

One final areas that folks have asked me about is relatively small accomocdation space. If I were comparing a 60' proa to a 60' catamaran my guess is that the cat would have 3x the interior space. Three times the area to add heads, electrical, plumbing, bunks and electronics. 3x the space to spend money. We're hoping to have the right amount of acomodation for our need. No more and no less. Once couple cruising with the occassional visitor (that means you Dave and Reza). The weather hull is 33' long and appears to have the same accomodations as a 42' monohull or a 36' catamaran. That's about right for us. There's an interesting link at the Wingo site which overlays a catamaran with a proa.

That's about it. We'll throw a bit into the mix about our rig decision and build method decision later on.

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