Sunday, July 10, 2011

The Va'a Motu


I've been working on a new 20' (6M) design lately that borrows some features of the Tahitian va'a motu.  The hollow clipper bow, the raised transom stern, the mixed attachments between the ama and the iakos, and the curved gull wing iakos are seen on the fast lagoon sailers in Eastern Polynesia.


The forward iako is made stiffer and stronger than the aft one.  The more flexible aft iako acts as a spring to allow the ama to change pitch with the water surface.


The leeboard and quarter rudder are arranged in a similar way to the Tamanu.  An outboard motor can be clamped on the ama side of the hull.  The long cockpit between the water tight bulkheads has a raised floor and is self bailing.  The 20' (6M) hull is flat bottomed and requires six sheets of 1/4" (6mm) plywood to construct.


The stayed rig is high aspect with a sheetlet sheeting system similar to junk sails.  The sheetlets control twist in the sail and make reefing as simple as it is with a junk rig.


This painting of a va'a motu by the late Herb Kane is based on drawings and accounts from Captain Cook's visit.
I've begun construction of the full scale prototype and hope to have it sailing in a few months.

33 comments:

Chris said...

Very lovely indeed. How do you think he will paddle?

DaveP said...

Tumeke Gary! I love it, still soaking up the details. Can't wait to see the prototype.

VectorGES said...

Beautiful, as usual.

Trevor said...

very nice!!!

Rotorhead said...

must add to cart...
-RH

Enter Miles said...

Nice, Gary

Proafile said...

Really lovely, Gary.

Gary.Dierking said...

This canoe is optimized for sailing rather than paddling. The high freeboard that helps to keep you dry when sailing fast can cause control problems if you try to paddle in a lot of wind, although you'll have no problem in calm weather. A pure paddler would have half this much freeboard.

Chris L. said...

Does the raised stern have any purpose--besides looking Tahitian? Do you send the kids back there on a blistering reach?

Gunnar said...

It looks similar to your "Tahitian tipairua" as an single outrigger and with flat bottom. Why not going with an shallow v-bottom?

Jon at Flsail.com said...

Wow, just cut out the frames for a Wa'apa. Should I just wait for the new plans to come out? Such pretty lines...It looks fast sitting still!

Jon at Flsail.com said...

What will the beam be?

I'd be ok with setting up the tall stayed rig, if I could just slide it on and off a trailer at the beach.

Gary.Dierking said...

The advantage of the high stern is yet to be proven. I don't think they used it just for style. Large catamarans have been built like that in Polynesia and the sailors like the way it fits up against a following wave face.
In this case I think the extra rocker aft will make for quicker tacking.

Gary.Dierking said...

I'm not convinced that there is much advantage to a shallow vee over a flat bottom. Certainly I have found that the absolute minimum draft is a big advantage where I sail, especially when launching or retrieving onto a trolley.

Gary.Dierking said...

If you have or a building a Wa'apa, it's not a big deal to build a new aft section with a stern like this. I will draw it up when all the testing is done.
The tall rig is based on a used 20' aluminum mast I got for $70. The sail will be cut down from an old Tornado sail I've got.

Jon at Flsail.com said...

Now I know what to do with the old main I have from my 28' San Juan!

Would be kinda fun to experiment with the Wa'apa stern section. I think I will continue building the first to spec, then perhaps play with creating a new stern section later.

Mike The Hammer said...

Can't wait to see it full sized. Makes me wish I were 6" tall.

seagypsy said...

What do you think the approx draft will be with a normal load, couple of people and some gear(30 to 40 lbs.)?

Sean said...

Absolutely fantastic Gary - About to start the Hull of my Tamanu. Amas and iakos complete (as good as) That clipper bow would look amazing - sorely tempted. SORELY TEMPTED

Wendell said...

Wow oh wow...cant wait to buy a set of plans. hope they will on your site soon. love to have it on the black sea next summmer...once again...wow!!!

Sean said...

Gary - Normally your Blog will get 1 or 2 comments - This time, 20 and counting!!! Seems you have stirred up a hornets nest?. Get your pencil out and start drawing - the beauty of the form will always out shine the function thereof. Not sure if a raised stern and clipper bow will have appreciable affect on performance - don't care either - But it'll look darn good in the process!!

Warren said...

Gary I just would like to say that is one of the most devastatingly beautiful boats I've ever seen! Certainly your best so far. I love every detail. Bravo sir! Cannot wait for the prototype. Keep the pics coming.

sooth said...

Gary "six sheets" Dierking, you styley muthafucka

sailing instructor said...

Seems to be fabulous for sailors since paddling is not needed, what is the maximum capacity of the vessel? Can it be recommended for learning sailors!

Gary.Dierking said...

It's a two person + cargo canoe. I'll need to sail it some more before recommending it to a beginner, but so far it looks good.

Peter A Haydon said...

Would it work as a tacking double outrigger or would the strong rocker/high stern make a stern rudder impractical?

Gary.Dierking said...

It would work fine as a double outrigger and that option will be included with the plans. A stern rudder would be a problem but I see no downside to a quarter rudder.

allan aunapu said...

Could this high stern have a slight step below to allow for plaining at high speeds? Please let me know more. I love this!

Gary.Dierking said...

team NZ tried something like that in the America's Cup. Sort of a flap to flatten out the run on reaches. I believe that it worked in some conditions but wasn't worth the extra complication. But of course that's no reason why you can't try it.

Christophe Journoud said...

Hi Gary,

What can you say about Va'a Motu and Tamanu differences in behavior at sailing ? They both are 6 meters in length and approx. the same beam / same wetted area.

Thanx.

Chris.

Christophe Journoud said...

And what about Va'a Motu rig on Tamanu's hull ?

Thanx

Chris.

Gary.Dierking said...

The main performance difference between the Tamanu and Va'a Motu is the better windward sailing ability of the Va'a Motu's high aspect rig. And yes, putting the Va'a Motu rig on the Tamanu would be fine and improve the tacking angles. The junk style sheeting saves the weight of a boom and reefing gear.
The Va'a Motu hull will still turn through tacks quicker, but having a jib on the Tamanu will make it turn quicker too.

Christophe Journoud said...

Thank you for your quick response.

Chris