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Building a 45ft Aluminum pacific proa!

King herog

New Member
First of all, if you don't know what a proa is than let me explain in short.

It's a multihull type boat. It looks like an asymmetrical catamaran because one hull is bigger than the other one and the mast is clearly out of center.
This is because the proa moves differently than a catamaran. It's a bit of a hybrid where there's only one hull who's always in the water while the other hull balances the forces of the wind.
This however makes for an interesting problem when you want to sail upwind. The way the proa keeps it ama (the windward hull) stay on the windward side is by shunting instead of tacking. A very different approach then you're used to seeing. This way the boat has no actual bow since it will sail in both directions.

Still don't understand?
Google ''shunting''
or watch my video explaining it in detail and comparing tacking and shunting:

I've been welding and grinding since october and now the ama is actually starting to look boatshaped.

Even better... It's mostly waterproof on the first pass of welding!

Check some other pics in the attachments!

It's been a blast making it and it's honestly a blast sharing the whole process.
So many questions still to be answered but so much fun already had!
I'm also keeping video updates on my youtube channel (king herog) since the beginning so I'm documenting it pretty well.
Here's my latest vid:
After a while I'll have some useful insights in welding aluminum for beginners so watch for a video about that.
Also to be found on instagram under the same name.

Following ideas I'd like to put in practice on this boat as a reference of what kind of project this is going to be:
2 wind generators of 400watts nominal power each
around 1000watts of solar panels
electric outboard engine
long term storage akas to make the boat a whole lott smaller and thus cheaper to store in a marina.
a autohelm autopilot combined with a raspberry pi opencpn plotter with a motessier hat on it to combine it into a full on autopilot.
casting my own kickers and other sail hardware
2 oak bowsprit sculptures by a friend
and plenty of other normal sailboat equipment

Wish me luck!
But I'm already having fun!


Cactus Cowboy

Well-Known Member
That's an interesting project... and heaps of work too! In a lifetime of sailing, I haven't seen too many aluminum sailcraft, just powerboats and some high-end yachts & trimarans. I still remember reading about Pen Duick IV, a 20.5m aluminum trimaran which was eventually rechristened and won the '72 Singlehanded Atlantic Race... sank at sea six years later, maybe it was a fraudulent insurance claim, LOL. Those big aluminum trimarans were fast in their day, and I imagine that proa you're building will scoot right along once you've finished your work. I didn't watch all of the videos, how tall will the rig be? And roughly how much sail area? :rolleyes:

Just curious, since those aluminum trimarans had fairly tall rigs... and this rig of yours looks to be shorter based on the model. Got any specific plans for voyages in the future? Inter-island voyages like the old proas used to make? Those Pacific Islanders were some serious sailors, their voyages were bad@$$ considering the islanders had no modern equipment, they just navigated by the stars and paid attention to natural signs at sea, like the presence of coconuts in a current or birds flying in a certain direction, LOL. What the hell, their methods worked: "GPS?!? WE DON'T NEED NO STINKING GPS!!!" ;)


Edit: Somehow, that last word reminds me of the story "YOUTH" by Joseph Conrad... a CLASSIC SEAFARING TALE with a similar ending to that of the rechristened Pen Duick IV, LOL. Always was considered bad luck to change the name of a ship... BTW, what are you going to name your craft? Or did you mention that in one of the videos? I reckon a Pacific Islander name or word(s) would be appropriate... something unique for a unique craft, AYE? :D
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King herog

New Member
First of all
Big thanks for all that positive energy.
It truly makes my day better!

Yeah there are definilty plenty of Alu sailboats out there but it seems that they love to just paint them all and hide the shiny aspect of it.

The initial cost of such a boat is also higher so it's not very common.
But I think it shines in maintenance.
Not actually needing paint and being so resistant to corrosion.
A very big plus for me.
Even though I'd love to go to Senegal or subtropical African country to paint the boat in the local pirogue style.
When in Senegal a boat arrived in the local marina with a very different color scheme and tbh it was so refreshing!!

And the boat is going to be Hella weird so why not make it more exentric.
It'll attract equally exentric people and that makes for interesting travels!

Sailrig wise it's still a big question.

It's obviously going to depend on budget.
I'm thinking first to go for a more modest setup of a second hand mast and some sails just to get to know the boat and not to have more power than I can handle.

So something of a 17m mast would be good to start. But this will depend on second hand markets.

Eventually I'd love a whole new rig but then I'll leave the calculations to someone who knows what they are doing.

So no definitive answer yet.

I do know the name already though
It's tupi (Brazilian tribe) language for big roar.

It's a tidal wave coming about twice a year into the Amazon and moving miles inland.

Since the pacific islanders likely came from south America and the boat is going to be roaring... Seemed like an good choice :)

And yes
One of the things I'd love to learn is celestial navigation.
I've got a little book about it and honestly it's not at all that difficult to do.
I'd be more irritated with trying to properly shoot the angle in rolling waves than any of the math.
You can get a precision of about 2km as well.
That's just crazy to me and a skill I'd love to have!

But yeah
The best way to keep updated is to go subscribe on my channel!
If you don't want to then just be patient and wait untill I have a question to ask on some forum or when I'd like to do some more promo for the project! ;p

Definitely love your enthusiasm!
Stay safe and healthy!
Cheers from me

Cactus Cowboy

Well-Known Member
I saw a film once with some hands surfing a tidal bore in Brazil, went for miles & miles... moi, farthest south I ever traveled was Panama. If I had more money, I'd like to travel through South America, especially along the Andes and down into Chile, Argentina & Patagonia. Funny we should have a town by that name right here in SE Arizona, I've been through it and there are no peaks like Fitz Roy & Cerro Torre, LOL. And I'm probably too old to tackle a peak like Cerro Torre, but I used to love reading the narratives of mountaineers & technical rock climbers who made the ascent, and I would still love to bivouac below the peak and simply enjoy the view... maybe bring a telescope to follow the progress of a climbing party high on that magnificent tower! :rolleyes:

Some peaks have an allure which others don't: Cerro Torre & the Trango Towers are good examples, perhaps because they're so difficult to climb. Not just climb, but also approach, though Cerro Torre is easier to reach than the Trango Towers. Again, if I had more money, I'd like to pull a wingsuit flight off the Great Trango Tower, even if I had to take a chopper ride to the summit... not sure modern choppers can fly that high though, so the world may have to wait for someone like Dean Potter to "Free-BASE" the tower. Dean's gone, but there will be others who step up... hey, I found a BASE jump video of the Great Trango Tower, but these fooliots don't look too skilled, unlike modern wingsuit pilots. Still, they're up there, though I would've picked a better day to jump, LOL. ;)

I also found a video of paragliding in Patagonia, can't tell if that's Cerro Torre though... might be, if that's Lago de Torre below in one part of the video. The video shows how difficult it is to position oneself for the jump, and that quick look at a huge avalanche is bad@$$, it looks like a huge waterfall, LOL. I wonder why no expert wingsuit pilots have attempted either peak, Cerro Torre or the Great Trango Tower? You'd think that some sponsors would step up and back such an expedition, not during this idiotic viral scare campaign but when things return to normal... meh, it will all be done in due time, these wingsuit heroes are like the new pioneers, LOL. I call it "3-D sailing" because that's what it is, with gravity tossed into the mix, and what legendary pioneers like Dean Potter & Jeb Corliss did in the past is amazing... they may be dead now, but their legacy will live forever on the Internet. :cool:


P.S. One more question: Will you install a trampoline or a safety net of some sort between hull & ama? :confused:
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New Member
That's the most exciting proa build I've seen this year, I think the size is the minimum for a cruising proa, thanks for sharing your work, it's inspiring.