The Secrets of the Wave Pilots

[jwhipple]

Article in the current NY Times Magazine about primitive navigation; the featured scientists include John Huth:

http://www.nytimes.com/2016/03/20/magazine/the-secrets-of-the-wave-pilots.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=mini-moth&region=top-stories-below&WT.nav=top-stories-below

[bbjorn]

Many thanks for posting this article.

During my two years on a remote W. Samoan island in the late '60s, not too far from the Marshall Islands, I was surprised and baffled by the fact that I almost never saw a local out in the open sea beyond the coral reef.  They spent much of their time fishing from outrigger canoes, but only within the calm lagoon -- despite the fish stock there being seriously depleted.  Their ancestors had traveled vast distances to settle these islands, but by all appearances the skills that brought them were sadly long lost.  In fact, when another volunteer and I talked with locals about our plan to paddle our canoes 50 miles, with an 8-mi. open ocean crossing and a difficult rocky landing, to attend the independence celebration in Apia, every Samoan we talked to thought we were insane and tried to dissuade us.  Returning to our villages two weeks later, we were surprised that news of our success/survival had preceded us despite a complete lack of modern communication.

Ever since, I've been fascinated and delighted by the resurgence among native Hawaiians and other Pacific peoples of interest in their ancient cultures and heritage, and especially their mysterious ancient navigation ability.  And having attended several of John Huth's wonderfully informative and entertaining NSPN presentations over the years, this article resonated doubly for me.

Blaine

 

Edited March 20, 2016 by bbjorn
grammar correction

[leong]

John,

What a great experience you had!

But even modern sloops are locked out of about a 90-degree arc centered on the wind’s direction. Based on my Sunfish’s performance, I’d guess that those Marshallese sailing canoes are locked out of at least a 110-degree arc, probably more like 150 degrees. I can’t get my head around how the ri-meto’s were able to feel the di lep and use it for navigation under such restricted sailing directions.

-Leon

 

[JohnHuth]

Hi, Leon - 

It was great, yes!

Here's my plot of the performance characteristics of the Jitdam Kapeel, based on a day of exercising it in the Majuro Lagoon.  The comparison vessel was a version of what became the Hokule'a - a double hulled vessel that's gotten a lot of publicity recently, with its round-the-world trip.   

When they sail into the wind, they 'shunt' the sails, rather than tack - this keeps the outrigger to windward all the time.   This also allows for an asymmetric hull shape that combats leeway.    

One problem with shunting is that it places the crew at risk when sailing in a heavy sea.    Alson Kelen, who was in charge of the expedition didn't want to risk shunting in a heavy sea on our outbound voyage, so we had to tow it some distance to calm water. 

[leong]

John,

That’s a pretty decent polar plot, as good as the Laser that I sometimes borrow and better than my Sunfish. I’m curious: Is it a plot of true wind speed true or apparent wind speed measured on the boat with an anemometer? And if true did you calculate it from apparent wind speed?

I guess the Jitdam Kapeel is a Proa. Does it have rudders on both ends, or is it sailed without rudders? I’ve been practicing sailing my Sunfish with the rudder up. It’s not too difficult in very light winds but almost impossible (for me) in heavier winds.

Leon

Edited March 24, 2016 by leong

[JohnHuth]

Hi, Leon - 

It's all true wind speed.   I was given a day and a crew to test out the performance characteristics in the Majuro Lagoon.   

I took an anemometer reading at rest when the sail was moved from one end to the other, also, I took readings when underway and noted the direction and speed, and then after a run, also took an anemometer reading.   For the readings under sail, I calculated the true wind from the apparent wind, direction and speed (from GPS).  I looked at the before-during-after readings for consistency.   The wind was reasonably stable over the course of any given run.

 

I suppose we could call it a proa - in the sense that the outrigger is always to wind and the sail is shifted from one side to the other when shunting (the proa version of tacking).   We didn't have rudders, but a large steering paddle that shifted from one end to the other.   Technically, it's called a tipnol in the Marshall Islands.

The hull is asymmetry to combat leeway and drag from the outrigger.   The leeway is quite small.   I have some video footage of the steering and also of the activity of moving the sail front-to-back.  

 

Best,

John

 

Edited March 30, 2016 by JohnHuth
minor correction