Praocargo 12m model on Vimeo. Cargo vessel could be the role the proa configuration will claim as its own. More soon.

The Fair Winds Trading Company.

Gauging the performance of an ancient Polynesian sail by The Polynesian Society.

——

Inspired by tales of the early American schooner trade (er… smuggling), I recently sat down to draw a multihull version of an inter-island or coastal cargo schooner. Monohull traders have been done a thousand times, but maybe something interesting might be had by an examination of the multihull.

My ideal cargo multihull would be manageable by a small crew, perhaps as few as 3 or 4. It would operate wherever the trade-winds provide consistent horsepower, enough to rely on. Cargo could be anything, from barrels of diesel to copra to tea, at least 5 tons of cargo capacity, 10 would be better.

And that’s when I ran into the problem of widely variable displacement on a multihull, because displacement x righting arm = righting moment, and righting moment governs everything else in the design of a sailing vessel. The long righting arm of the multihull multiplies displacement into a formidable beast.

For yachts, the displacement does not vary too much once the crew and stores are aboard. Yes, water, food and fuel come and go over the course of a voyage, but cargo is another matter. Laden displacement of a cargo vessel could be 4-5 times the empty weight.

See Fig. 2 (in gallery above), which compares righting arms of a generic 10m cat, trimaran, monohull - and a proa. The trimaran is the worst case, having a righting arm a full 7.5 times the length of the monohull. The cat’s arm is 4.5 times the mono. Like monohulls, cargo on multihulls is loaded on centerline (a cat would load both hulls as equally as possible to get the same result). The loads on the structure of a heavily laden catamaran or trimaran will be immense.

It is prudent to design for worst case, or the most laden condition (which is also “best case” for the skipper, since his boat is full of goods to be sold). A heavily laden multihull has an enormous righting moment, leading to bigger sails, greater stresses, larger and stronger structural members, adding even more weight, and up the design spiral we go. The vessel quickly becomes expensive to build, maintain and to operate, cutting into profit and the reason for building the boat in the first place. Conversely, when the multihull is lightly laden it is needlessly overbuilt and over-canvased.

The only way around this conundrum is with the proa, which does not require bilateral symmetry.

On a proa, cargo may be loaded entirely into the leeward hull, which is also the center of buoyancy. There will be very little change in righting moment no matter how heavily laden the proa might be (within reason, we are not talking about submerging the decks here). With a proa, righting moment is handled by the weighted ama and outrigger structure to windward, not buoyancy to leeward. The righting moment remains consistent, meaning stress, scantlings and sail area will also remain consistent between laden and unladen. This leads to a well-engineered and efficient structure through a widely varying displacement.

Conceptually, the proa decouples the driving force from the overall displacement. Sailing loads do not skyrocket as cargo is loaded. The ship should sail and handle much the same whether laden or unladen, the only difference being speed attained.

The handling problems of a proa still remain - shunting is more trouble than tacking. However on long voyages, particularly in the trades, the necessity for tacking is reduced. Besides, if the economics pan out, then the captains of cargo proas may consider the handling trade-off to be well worth it.

When lightly laden, the proa would still be capable of the speeds that made them famous. This will make for fast return passages, as well as spirited racing. After all, every cargo schooner must race!

See Understanding monohull sailboat stability curves by Matthew B. Marsh for a good primer on righting moments.

The Adventurists Max Lowe and his new friends are taking the road less traveled on a ten-day adventure along the Sea of Cortez in Baja California, Mexico. Austin Kino gives us a tour of the Hawaiian sailing outrigger Holopuni. From National Geographic. Navigating Baja: Bringing Hawaiian Sailing to Mexico

A report by Peter Adrian from Sweden on his crab claw rigged iceboat:

Am sailing my second season my modified iceboat: an Isabella Classic with 5m2 (54 sq. ft.) crab claw sail. Just a win-win over all compared against the same boats with conventional Bermuda rig. Just one thing I’ve noticed is she no longer lifts the windward runner at over 60km/h (37 mph).

The yard is made fast to the apex of a bipod mast and fixed to the hull at the bow, so it cannot move. Like the traditional oceanic rig, only the boom is free to sheet in and out. Iceboats are sailed close-hauled at all times, and tack downwind, so the narrow sheeting range between the bipod is no problem.

The sail is cut dead flat, so it is the simplest of rigs for the home builder. Another advantage is the iceboat can be parked in its box more or less completely rigged. Pull the sack off the spars/sail, lift the yard and clip it to the bipod mast. Install the runners and the sled is ready to go in 5-6 minutes, while the Bermudas are still still fighting to get their stuff ready in 20-30 minutes, and even longer if minus 5C.

Peter’s Isabelle Classic fleet: The G-Flyers

Peter also sails a Viking ship. Really.

BROOMSTICK is a 15’ home-designed & built hydrofoil trimaran by Doug Halsey. It first sailed as a foiler in 2004 and has been refined gradually each year since then (only sailing a handful of times per year). Although it wasn’t intended to be the ultimate in speed, it routinely exceeds 20 knots, with a lifetime best speed of 28.7 knots. Box section hulls, round aluminum tube beams, deep-V hydrofoils and used beach cat sails - what’s not to like?

—-

Tarpon Springs FL based smallcraft designer/builder JF Bedard has posted an informative recap of his experience racing the 2017 Everglades Challenge in his self-designed and built micro-cruiser: RoG. Great for any fan of long-distance challenges like the EC and the R2AK. Besides, I am especially taken with Bedard’s diminutive racer, its distinct lack of multiple hulls notwithstanding. Bedard Yacht Design.

The original CSK Polynesian Concept 35 is for sale in Newport Beach, CA. This boat was designed and built for Buddy Ebsen, the actor and TV star best remembered for his role as Jeb Clampett in the CBS sitcom The Beverly Hillbillies. The listing dealer appears to be banking on the star power of the yacht, but the listing is still worth a look due to the good photos.

The third annual Race to Alaska starting gun goes off at 5:00 am on June 8. 750 miles, no motor, no support from Port Townsend WA to Ketchikan AK. As per the previous races, there will be plenty of multihulls vying for the $10,000 first to finish prize, and perhaps a new course record, though last year’s time of 3d 20h 13m set by Team MAD Dog Racing is a tall order.

New this year is the Buy Back offer: Each team that finishes and rings the bell will get 5 minutes to decide whether or not they will be the one to sell R2AK their boat for $10,000. Buy an old Hobie for a thousand, race to Alaska, make $9K. What could possibly go wrong?

There are 21 multihull teams signed up for the full race:

1. Team Triceratops from Frisco on a Corsair F-27
2. Team Pure & Wild/Freeburd from Marblehead, MA on Mama Tried, a custom 8.5m Melvin trimaran
3. Team Phocoena from Paris, France on a Tricat
4. Team Nomadica from Victoria BC on a Windrider 17
5. Team Ketch Me If U Can from Frisco on a Nacra Inter 20
6. Team PT Watercraft from Port Townsend WA on a Gougeon 32
7. Team Bitty Kitty Meow from Lake Forest Park WA on a Nacra 17
8. Team Bad Kitty from Surrey BC on a 34’ yellow catamaran
9. Team Big Broderna from Anacortes WA on a F31 trimaran
10. Team Uncruise from Juneau AK on a Farrier 25C
11. Team Make It So from Seattle, WA on a Prindle 19r
12. Team Northwest Wind & Surf from Seattle WA on a Dierking Tamanu trimaran
13. Team Campbell Sloop from Sqaumish BC on custom Angus trimaran
14. Team Sistership from Ventura CA on a Corsair F-27
15. Team Gar from Charlottesville, VA on a 19’ Tri-raid trimaran
16. Team What the Fuca from somewhere south on Corsair F-28
17. Team Sailpro from Isle of Wight UK on a 34’ Crowther Buccaneer trimaran
18. Team 3 1/2 Aussies from Vancouver BC on a F-31
19. Team Kairos from New Canaan CT on a 19’ Angus Rowcruiser
20. Team Pear Shaped Racing from San Francisco/Victoria BC on a Multi 23 trimaran
21. Team Discovery from Taylor SC on a Hobie 16

Best of luck to all the teams, and don’t get eaten by a bear.

Follow the race at R2AK.com, and on Facebook and Twitter.

If you are planning on attending the pre-race Ruckus the day before, give me a shout for a meet up.

Duckworks has a nice interview with one of our favorite canoe designer/builders.

When did you become a boat designer and what was your first real design? I started drawing boats when I was about eight years old, and I built my first one at fifteen from a photo in a magazine. That first project was an eight foot lake scow with an underbody similar to the current Puddle Ducks…

Celebrated New Zealand artist and designer David Trubridge has turned his creative attention back to boats, where it all began. Trubridge studied naval architecture in his native England, and sailed his small family on a journey that took them to the Caribbean and Polynesia, working their way from place to place, eventually landing and settling in New Zealand. His wooden furniture and lighting designs are now exhibited and sold in trade fairs worldwide.

A key chapter in the book (So Far) looks at boats and the question, why are traditional boats from every corner of the planet invariably so beautiful, despite an incredible variety of form? I could not resist launching on a practical exploration of boat forms that combined my naval architect training with my experience at building shell forms for lighting using CAD.

Some of the finest seafarers of all time have been the Polynesians, who have made some of the fastest and most beautiful boats. Their creations include the crab claw sail, proven to be the most efficient overall sail ever designed; and the amazing thofothofo from Aua and Wuvulu Islands which is as unique as it is impossibly beautiful. But to what extent is beauty a consideration for the Polynesian canoe maker? Or is it more of a practical tool for achieving the perfect form?

David has utilized his modern skills and technique of CAD, a CNC router and ultra thin plywood to build his own version of ancient designs, including a British coracle, a thofothofo outrigger canoe and a dugout river canoe. He has also turned his attention to exquisite stand up paddle boards.

Beauty Matters, the Boat Project Part 1
Beauty Matters, the Boat Project Part 2

BOOK REVIEW: ‘So Far’ Traces the Evolution of David Trubridge’s Nature-Inspired Designs
David Trubridge on Facebook

Much thanks to Paul D. for the submission.

Alex Calothis has submitted his progress on a proa build in Greece.

I grew up in Athens and learnt to sail on optimists when I was about 8, and I have loved sailing ever since.

My father built a 6m catamaran around that time, and it was very fast, but would not turn very easily - long narrow hulls with very little rocker. We often had to perform a three point turn to get her around!! Still, she was a lot of fun. Later he bought a charter yacht and worked as a yacht skipper for about 30 years. I’ve also worked as a skipper for a while.

I’ve had a dream for many years to build a boat, and my father introduced me to the idea of the proa - he was very interested in the early western proas that were built to break speed records. The layout just makes sense to me. This is the first boat I have built. I started about two years ago, but I am not in Greece much these days, maybe a month or two in the summer, so progress is slow. I’m enjoying the build process!

Particulars

• Vaka (main hull): LOA 7.5m. LWL 7m, Beam 0.7m (beam waterline is less - about 50cm)
• Ama (outrigger): LOA 5m, LWL 4.8m, Beam 0.35m
• Beam from hull centers: 3.5m.

The vaka was designed with Freeship, and the ama is a box section, but on set on edge, like a diamond. Construction is 8mm marine ply stitch & glue, sheathed in ‘glass. The akas (cross beams) are box sections out of 20mm spruce (I don’t think it’s proper spruce - I got it from the local wood shop). I can jump up and down on the one that I have finished and it doesn’t flex much at all. It is sheathed in a carbon fiber ‘sock’. I hope it’s strong enough. The akas will be lashed to the deck of the vaka, and there are solid oak beams that go all the way through the vaka below the gunwale to accept the lashings. I’m still working out the best way to connect the akas to the ama. The posts sticking up out of the ama are also solid oak.

I will try either a crab claw sail, with the mast stepped on a ‘bridge’ that will run from one aka to the other, perhaps 50cm to windward of the vaka, or two masts and a sloop rig, with each mast stepped directly onto the akas. Although I expect first trials will be conducted using a kitesurfing kite, because I’m impatient!

Rudders will hang from posts that you can see in the photos sticking out of the vaka to windward, and they will rotate a full 180 degrees so that the leading rudder can just trail when it is not in use.

I have made a solid spruce daggerboard, routed to an ogive section, and there is a daggerboard slot in the vaka, but I have not yet cut out the hole for it at the bottom of the hull, and to start with I will try the boat without it. I may or may not use this in the future.

Originally I designed a 10m vessel, and the hull that I am using as the vaka was actually designed as an ama for this 10m proa.

The hull is designed to take on water ballast, if I ever use it as the ama for a larger vessel, like CLC’s MADNESS, which provided inspiration for the design.

Thanks for the progress report Alex, and I must say this looks likes the most pleasant work shop I have ever seen! -Editor

French designer Jérôme Delaunay has completed plans for a 9.9m (32’-6”) cruising proa named VAKA 990. It is a “pacific” type that includes four berths, a WC and some storage. The proa features a free-standing schooner rig of 37.25 m2 (400 sq. ft.) and central daggerboard in the main hull. Steering is via outboard mounted (Viking-style) rudders fore and aft. The central accommodations pod extends out to leeward to function as “anti-capsize” buoyancy at angles of heel over 30°. Construction is plywood/epoxy. In some views there appears to be a hatch with bubble canopy in the ama which could provide an enclosed helm position.

If ever a proa could be called simple, practical and conservative, the VAKA 990 would be it. Plans are available here for €600. Read more about Delaunay’s work on Facebook and Nautline.

Harryproa has been busy of late. Here’s a nicely modeled proposal for the new VOR Inshore Foiler races. It is, naturally, a proa in configuration, but that is where the similarity to a Pacific sailing canoe ends. The fully foiling triscaph may be vapor-ware at the moment, but considering the obvious thought that went into the proposal from shipping logistics to VIP guest seating we hope this one makes it to prototype stage. Read Rob Denney’s full proposal here. More on the design at Cat Sailing News, and on Facebook.

Jan Stute and Siegfried Wagner have designed and built a modular camp-cruiser proa that was recently exhibited at Hanseboot in Hamburg. The design is based on a classic Pacific island sailing canoe, or walap, including a crab claw sail and deep-V asymmetrical hull, though realized in modern plywood and epoxy. The hull comes apart into three sections to make storage and transport more flexible.

We like the optional canoe dinghy, which doubles as an anti-capsize float.

Read more at the blog: werftprojecte.

Thanks to Proafile reader Aquiles for the submission.

Praocargo 12m model on Vimeo. Cargo vessel could be the role the proa configuration will claim as its own.

Shipping may be the most energy-efficient mode of cargo transport, but small ships transporting less than 4% of world cargo contribute 26% of all shipping emissions.

Advances in racing technology give us the tools to design a boat that is fast, light, and able to sail close to the wind, allowing us to open up sailing trade routes that have not existed in modern times. We are applying cutting-edge, ecologically-conceived designs to ancient transport boats of the south Pacific – the newest of everything – from energy recuperation systems to lightweight, strong, low-impact materials will be utilised.

The Fair Winds Trading Company.

Gauging the performance of an ancient Polynesian sail by The Polynesian Society.

Inspired by tales of the early American schooner trade (er… smuggling), I recently sat down to draw a multihull version of an inter-island or coastal cargo schooner. Monohull traders have been done a thousand times, but maybe something interesting might be had by an examination of the multihull.

My ideal cargo multihull would be manageable by a small crew, perhaps as few as 3 or 4. It would operate wherever the trade-winds provide consistent horsepower, enough to rely on. Cargo could be anything, from barrels of diesel to copra to tea, at least 5 tons of cargo capacity, 10 would be better.

And that’s when I ran into the problem of widely variable displacement on a multihull, because displacement x righting arm = righting moment, and righting moment governs everything else in the design of a sailing vessel. The long righting arm of the multihull multiplies displacement into a formidable beast.

For yachts, the displacement does not vary too much once the crew and stores are aboard. Yes, water, food and fuel come and go over the course of a voyage, but cargo is another matter. Laden displacement of a cargo vessel could be 4-5 times the empty weight.

See Fig. 2 (in gallery above), which compares righting arms of a generic 10m cat, trimaran, monohull - and a proa. The trimaran is the worst case, having a righting arm a full 7.5 times the length of the monohull. The cat’s arm is 4.5 times the mono. Like monohulls, cargo on multihulls is loaded on centerline (a cat would load both hulls as equally as possible to get the same result). The loads on the structure of a heavily laden catamaran or trimaran will be immense.

It is prudent to design for worst case, or the most laden condition (which is also “best case” for the skipper, since his boat is full of goods to be sold). A heavily laden multihull has an enormous righting moment, leading to bigger sails, greater stresses, larger and stronger structural members, adding even more weight, and up the design spiral we go. The vessel quickly becomes expensive to build, maintain and to operate, cutting into profit and the reason for building the boat in the first place. Conversely, when the multihull is lightly laden it is needlessly overbuilt and over-canvased.

The only way around this conundrum is with the proa, which does not require bilateral symmetry.

On a proa, cargo may be loaded entirely into the leeward hull, which is also the center of buoyancy. There will be very little change in righting moment no matter how heavily laden the proa might be (within reason, we are not talking about submerging the decks here). With a proa, righting moment is handled by the weighted ama and outrigger structure to windward, not buoyancy to leeward. The righting moment remains consistent, meaning stress, scantlings and sail area will also remain consistent between laden and unladen. This leads to a well-engineered and efficient structure through a widely varying displacement.

Conceptually, the proa decouples the driving force from the overall displacement. Sailing loads do not skyrocket as cargo is loaded. The ship should sail and handle much the same whether laden or unladen, the only difference being speed attained.

The handling problems of a proa still remain - shunting is more trouble than tacking. However on long voyages, particularly in the trades, the necessity for tacking is reduced. Besides, if the economics pan out, then the captains of cargo proas may consider the handling trade-off to be well worth it.

When lightly laden, the proa would still be capable of the speeds that made them famous. This will make for fast return passages, as well as spirited racing. After all, every cargo schooner must race!

See Understanding monohull sailboat stability curves by Matthew B. Marsh for a good primer on righting moments.

The Adventurists Max Lowe and his new friends are taking the road less traveled on a ten-day adventure along the Sea of Cortez in Baja California, Mexico. Austin Kino gives us a tour of the Hawaiian sailing outrigger Holopuni. From National Geographic. Navigating Baja: Bringing Hawaiian Sailing to Mexico

A nearly complete 38’ Echo class trimaran by Richard Newick has become available in NSW Australia. Deceased Qantas First Officer and boat builder Graham Murray’s family must liquidate the project. Build of foam sandwich with carbon reinforcement, the boat was lengthened to 38’ during construction.

The listing also includes fittings and equipment, all new: outboard motor, mast, boom, rudder, tiller, winches, sails, hatch covers, assorted tools and glue, ropes, anchors, water filtration unit, water maker, toilet, solar panels, electronics and more. View the complete listing here.