*

Offline GreatATuin

  • *
  • Posts: 310
  • It's turtles all the way down
    • View Profile
Vendée Globe
« on: November 11, 2020, 10:36:24 AM »
Two days ago, 33 sailors have set sail from Les Sables d'Olonne, France. The Vendée Globe is a solo non-stop round-the-world race, along the Clipper route.



It's a tough race: typically, only half the sailors make it to the finish line.

https://www.forbes.com/sites/tmullen/2020/11/09/the-insanity-and-elegance-of-the-vende-globe-sailing-race

https://www.espn.com/olympics/story/_/id/30249677/bubbles-separation-solitude-trying-cope-2020-let-examine-vendee-globe

Their progress can be tracked online : https://www.vendeeglobe.org/en/tracking-map

On a flat bipolar Earth, this kind of circumnavigation is not possible. On a flat monopole Earth, it could be possible, but the southern part along the roaring forties would be much longer.

Are these sailors and the race organization part of a conspiracy?
Nearly all flat earthers agree the earth is not a globe.

you guys just read what you want to read

*

Offline RhesusVX

  • *
  • Posts: 187
  • 1/137.03599913
    • View Profile
Re: Vendée Globe
« Reply #1 on: November 11, 2020, 03:35:01 PM »
Two days ago, 33 sailors have set sail from Les Sables d'Olonne, France. The Vendée Globe is a solo non-stop round-the-world race, along the Clipper route.

On a flat bipolar Earth, this kind of circumnavigation is not possible. On a flat monopole Earth, it could be possible, but the southern part along the roaring forties would be much longer.

Are these sailors and the race organization part of a conspiracy?

I can only see three viable options here:
  • The sailors and the race organisation are all part of a big global conspiracy to make everybody else think that the Earth is round
  • The sailors and the race organisation are simply victims (like we are) of a big global conspiracy by using technology that has been engineered to make it seem like the Earth is round
  • The sailors and the race organisation are not part of any conspiracy, and they are simply circumnavigating the Earth which we know to be a globe with known distances between land masses
Per the thread talking about the burden of proof, which of the above sounds the most ludicrous?  The more ludicrous it sounds, the more it lends credibility to the opposing view.

Having said that, the race is about 21,600 miles long, so it would probably be in the region of 60,000 miles if the Earth were flat and they just travelled around it in a circle.  Just like the land masses and known distances between them, FET cannot account for the massive discrepancies we get, especially involving the "southern hemisphere".
Quote from:  Earth, Solar System, Oort Cloud, LIC, Local Bubble, Orion Arm, Milky Way, Local Group, Virgo Supercluster, Laniakea Supercluster, Universe
"Sometimes you need to take a step back to see the bigger picture, and sometimes you need to think outside the box dome"

Re: Vendée Globe
« Reply #2 on: November 11, 2020, 05:19:44 PM »
Without prejudging the possible responses, this would be a great project for investigation. Chart the progress of the yachts day by day on an FE-style map versus an RE map, compare distances and average speeds from the telemetry and as derived from an FE map and make comparisons. I’m sure it would be fascinating!

Just one caveat - anyone who wants to accuse the sailors of fraud or cheating better do it from a great distance: they’re a tough lot, liable to react badly to being accused to their faces. You might get an unexpected cold, salty bath.
Once again - you assume that the centre of the video is the centre of the camera's frame. We know that this isn't the case.

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #3 on: December 02, 2020, 03:50:04 PM »
Here's their position Dec. 2, 2020



At the time, the leading boat (Apivia) has sailed 9,132.9nM (16,914.1km) and has 16,945.2nM (31,382 km) remaining currently headed from the Cape of Good Hope to Australia.

If you plot their course on the WIKI approved FE map, there would be roughly the same distance to travel (using the most FE favorable translation of route) from the Cape to Cape Leeuwin.



We'll see how the next stretch goes.
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #4 on: December 14, 2020, 04:12:01 PM »
Been a fun little exercise following this race.  The leader passed Cape Leeuwin, Australia looks to be sometime Dec. 13.



Apivia at that time had traveled 24.787 Km.  That puts Apivia 7873 Km further than my previous Dec. 2 update slightly past the Cape of Good Hope.

In my previous post, I mapped out on the WIKI FE map how based on the nearly 17,000 Km from France to the Cape would correlate to another 17,000 Km from the Cape to Cape Leeuwin, we can see that the WIKI map is simply flat out wrong, by a significant margin.
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

*

Offline Tom Bishop

  • Zetetic Council Member
  • **
  • Posts: 8248
  • Flat Earth Believer
    • View Profile
Re: Vendée Globe
« Reply #5 on: December 14, 2020, 05:44:18 PM »


On a flat monopole Earth, it could be possible, but the southern part along the roaring forties would be much longer.

Why are they called the roaring forties and furious fifties?

It's because there are are abnormal winds there, which will necessarily put the water into motion and anything on top of it.

http://www.antarctica.gov.au/magazine/2001-2005/issue-4-spring-2002/feature2/what-is-the-southern-ocean

  “ The Southern Ocean is notorious for having some of the strongest winds and largest waves on the planet. ”

http://www.bbc.com/earth/story/20151009-where-is-the-windiest-place-on-earth

  “ There are huge belts of wind caused by the uneven way the Sun heats the Earth's surface. 30° north and south of the equator, the trade winds blow steadily. At 40° lie the prevailing westerlies, and the polar easterlies begin at around 60°.

Ask any round-the-world sailor and they will quickly tell you the stormiest seas, stirred by the strongest winds, are found in the Southern Ocean. These infamously rough latitudes are labelled the "roaring 40s", "furious 50s" and "screaming 60s". ”

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003JD004179

  “ The Southern Ocean is a vital element in the global climate. Its circumpolar current plays a crucial role in the global transport of mass, heat, momentum, and climate signals from one ocean basin to another. Moreover, the Southern Ocean hosts the strongest surface winds of any open ocean area, fostering strong heat, moisture, and momentum exchanges between the ocean and atmosphere. However, the Southern Ocean is tremendously undersurveyed by traditional observation methods because of the remoteness of the area and rough environment, causing the largest data gap of global oceans. ”

https://books.google.com/books?id=MxmUDwAAQBAJ&lpg=PA103#v=onepage&q&f=false

  “ The higher speed and greater persistence of the westerlies in the Southern Hemisphere are caused by the difference in the atmospheric pressure patterns as well as its variation from that of the Northern hemisphere. The landmass in the southern hemisphere is comparatively less and average annual pressure decreases much more rapidly on the pole ward side of the high pressure belt. ”

https://www.cia.gov/library/publications/the-world-factbook/geos/print_oo.html

  “ the ocean area from about latitude 40 south to the Antarctic Circle has the strongest average winds found anywhere on Earth ”
« Last Edit: December 14, 2020, 05:51:35 PM by Tom Bishop »
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #6 on: December 14, 2020, 06:46:56 PM »


On a flat monopole Earth, it could be possible, but the southern part along the roaring forties would be much longer.

Why are they called the roaring forties and furious fifties?

It's because there are are abnormal winds there, which will necessarily put the water into motion and anything on top of it.

http://www.antarctica.gov.au/magazine/2001-2005/issue-4-spring-2002/feature2/what-is-the-southern-ocean

  “ The Southern Ocean is notorious for having some of the strongest winds and largest waves on the planet. ”

http://www.bbc.com/earth/story/20151009-where-is-the-windiest-place-on-earth

  “ There are huge belts of wind caused by the uneven way the Sun heats the Earth's surface. 30° north and south of the equator, the trade winds blow steadily. At 40° lie the prevailing westerlies, and the polar easterlies begin at around 60°.

Ask any round-the-world sailor and they will quickly tell you the stormiest seas, stirred by the strongest winds, are found in the Southern Ocean. These infamously rough latitudes are labelled the "roaring 40s", "furious 50s" and "screaming 60s". ”

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003JD004179

  “ The Southern Ocean is a vital element in the global climate. Its circumpolar current plays a crucial role in the global transport of mass, heat, momentum, and climate signals from one ocean basin to another. Moreover, the Southern Ocean hosts the strongest surface winds of any open ocean area, fostering strong heat, moisture, and momentum exchanges between the ocean and atmosphere. However, the Southern Ocean is tremendously undersurveyed by traditional observation methods because of the remoteness of the area and rough environment, causing the largest data gap of global oceans. ”

https://books.google.com/books?id=MxmUDwAAQBAJ&lpg=PA103#v=onepage&q&f=false

  “ The higher speed and greater persistence of the westerlies in the Southern Hemisphere are caused by the difference in the atmospheric pressure patterns as well as its variation from that of the Northern hemisphere. The landmass in the southern hemisphere is comparatively less and average annual pressure decreases much more rapidly on the pole ward side of the high pressure belt. ”

https://www.cia.gov/library/publications/the-world-factbook/geos/print_oo.html

  “ the ocean area from about latitude 40 south to the Antarctic Circle has the strongest average winds found anywhere on Earth ”

Great info, Tom.  Absolutely meaningless when talking about the fact that the distance covered over the last 9 days is roughly 1/2 the distance required if the route is plotted on the WIKI flat earth map.  It's really basic.  You can't peel the spherical earth from the north pole onto a flat map and keep the lines of longitutde without vastly distorting the measurable longitudinal distances the further you go into the southern hemisphere.
« Last Edit: December 14, 2020, 06:58:56 PM by WTF_Seriously »
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

*

Online stack

  • *
  • Posts: 1908
    • View Profile
Re: Vendée Globe
« Reply #7 on: December 14, 2020, 06:47:37 PM »


On a flat monopole Earth, it could be possible, but the southern part along the roaring forties would be much longer.

Why are they called the roaring forties and furious fifties?

It's because there are are abnormal winds there, which will necessarily put the water into motion and anything on top of it.

http://www.antarctica.gov.au/magazine/2001-2005/issue-4-spring-2002/feature2/what-is-the-southern-ocean

  “ The Southern Ocean is notorious for having some of the strongest winds and largest waves on the planet. ”

And the next sentence from you link is: "It is also home to the largest current in the world ocean, the Antarctic Circumpolar Current. The Circumpolar Current carries between 135 and 145 million cubic meters of water per second from west to east along a 20,000km long path around Antarctica."

So I guess this would refer to a bi-polar flat earth model?

http://www.bbc.com/earth/story/20151009-where-is-the-windiest-place-on-earth

“ There are huge belts of wind caused by the uneven way the Sun heats the Earth's surface. 30° north and south of the equator, the trade winds blow steadily. At 40° lie the prevailing westerlies, and the polar easterlies begin at around 60°.

Ask any round-the-world sailor and they will quickly tell you the stormiest seas, stirred by the strongest winds, are found in the Southern Ocean. These infamously rough latitudes are labelled the "roaring 40s", "furious 50s" and "screaming 60s". ”

Correct and from your link:

"This depression boosts the trade winds that blow towards the equator. The column of rising air spins due to the Coriolis effect, whereby the rotation of the Earth deflects winds away from the equator."

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003JD004179

  “ The Southern Ocean is a vital element in the global climate. Its circumpolar current plays a crucial role in the global transport of mass, heat, momentum, and climate signals from one ocean basin to another. Moreover, the Southern Ocean hosts the strongest surface winds of any open ocean area, fostering strong heat, moisture, and momentum exchanges between the ocean and atmosphere. However, the Southern Ocean is tremendously undersurveyed by traditional observation methods because of the remoteness of the area and rough environment, causing the largest data gap of global oceans. ”

From the first line of the abstract in your link, "Space‐based scatterometer instruments provide crucial surface wind measurements with high resolution over global oceans."

Are you referencing global satellite data now?


https://books.google.com/books?id=MxmUDwAAQBAJ&lpg=PA103#v=onepage&q&f=false

  “ The higher speed and greater persistence of the westerlies in the Southern Hemisphere are caused by the difference in the atmospheric pressure patterns as well as its variation from that of the Northern hemisphere. The landmass in the southern hemisphere is comparatively less and average annual pressure decreases much more rapidly on the pole ward side of the high pressure belt. ”

Your link also describes latitudes as: "Latitudes specify the North-South position of a location on the globe." As well as many references to earth's rotation and orbit around the Sun.

https://www.cia.gov/library/publications/the-world-factbook/geos/print_oo.html

  “ the ocean area from about latitude 40 south to the Antarctic Circle has the strongest average winds found anywhere on Earth ”

The first sentence of your link is, "A large body of recent oceanographic research has shown that the Antarctic Circumpolar Current (ACC), an ocean current that flows from west to east around Antarctica, plays a crucial role in global ocean circulation."

It seems that all or your references and explanations are decidedly Globe centric.
Not much is known about the celestial bodies and their distances.

*

Offline Iceman

  • *
  • Posts: 655
  • where there's smoke there's wires
    • View Profile
Re: Vendée Globe
« Reply #8 on: December 14, 2020, 06:50:59 PM »
This is a a great case study to look at issues with the FE map, though there are other variable at play that Tom has pointed out, the differences between distances plotted on globe-based maps and the most prominent FE map are staggering.

Appealing to 'exaggerated distances in the hemisphere' creates another issue, because if the world was indeed flat, map making should be simple --no need for complicated projections that necessarily skew the size, distance, shape, or positions of depicted features.

It would be relatively straightforward for one to compare the progress of the racers and compare their speeds to reported weather conditions to evaluate whether the mean seas of the south could account for all of the apparent changes in speeds interpreted from the FE and globe-based maps.

Tom posted some quotes on the nature of weather systems in this region, from sources he likely views as trustworthy... I wonder what else those sources might say about the causes of those weather systems...

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #9 on: December 14, 2020, 07:01:48 PM »
This is a a great case study to look at issues with the FE map, though there are other variable at play that Tom has pointed out, the differences between distances plotted on globe-based maps and the most prominent FE map are staggering.

Appealing to 'exaggerated distances in the hemisphere' creates another issue, because if the world was indeed flat, map making should be simple --no need for complicated projections that necessarily skew the size, distance, shape, or positions of depicted features.

It would be relatively straightforward for one to compare the progress of the racers and compare their speeds to reported weather conditions to evaluate whether the mean seas of the south could account for all of the apparent changes in speeds interpreted from the FE and globe-based maps.

Tom posted some quotes on the nature of weather systems in this region, from sources he likely views as trustworthy... I wonder what else those sources might say about the causes of those weather systems...

Hover over any vessel on the tracking map and it will tell you their telemetry at that point in time.  For the FE model to be accurate if you compare the mostly N-S distance traveled over the first 21 ish days and put that distance over the last 9 days the vessels would have to average something around 30 knots.  You can see on the tracker that much of the time the vessels are under 20.  Just a quick calc. puts their average a little over 16.
« Last Edit: December 14, 2020, 10:36:55 PM by WTF_Seriously »
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #10 on: December 15, 2020, 04:11:03 PM »
Over the next couple weeks we'll be able to track the Tasmania to Cape Horn route.



If you use the length of the route on the FE map and compare it to the already completed track it comes in at roughly 25,000 Km (gave the FE map about 2,500 Km in their favor in my estimation.)  Even a straight line course on the FE map would be around 20,000 Km.  Don't think many will find it surprising when the actual route comes in at less than 10,000 Km.

« Last Edit: December 15, 2020, 04:20:53 PM by WTF_Seriously »
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

*

Offline Tom Bishop

  • Zetetic Council Member
  • **
  • Posts: 8248
  • Flat Earth Believer
    • View Profile
Re: Vendée Globe
« Reply #11 on: December 15, 2020, 04:19:38 PM »
It is tremendously and abnormally windy in that area. An assessment would need to take that into account.
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #12 on: December 15, 2020, 04:29:26 PM »
It is tremendously and abnormally windy in that area. An assessment would need to take that into account.

Why?  The wind has nothing to do with the distances being traveled.  We aren't talking about the time required to get from point A to point B.  We are discussing the distance.  As I mentioned in my previous post, the vessels track their speed.  The FE speed required is nearly double the measured speed to get from Cape of Good Hope to Cape Leeuwin in the time traveled if the FE distance was actually correct.

Edited to add: The last update shows the leader in 3M seas and 21.8 Knot winds.  Though significant, hardly tremendous or abnormal by sailing standards.
« Last Edit: December 15, 2020, 06:12:03 PM by WTF_Seriously »
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

*

Offline Tom Bishop

  • Zetetic Council Member
  • **
  • Posts: 8248
  • Flat Earth Believer
    • View Profile
Re: Vendée Globe
« Reply #13 on: December 15, 2020, 06:24:48 PM »
The formula for speed is Speed = Distance / Time

If the distance is in question, then the speed is also in question.

The situation is fluids traveling within fluids. The winds and water are in motion. On board airplane airspeed indicators are similarly unreliable, and are not used for navigation. The local area of the airplane might be in motion faster than a larger area around that airplane, which might itself be in motion.
« Last Edit: December 15, 2020, 06:29:05 PM by Tom Bishop »
"The biggest problem in astronomy is that when we look at something in the sky, we don’t know how far away it is" — Pauline Barmby, Ph.D., Professor of Astronomy

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #14 on: December 15, 2020, 06:25:07 PM »
The formula for speed is Speed = Distance / Time

If the distance is in question, then the speed is also in question.

The speed is measured relative to the water.  That's how boats measure speed.  They don't get there and then say, "Well, we traveled this far in the past 24 hours so we were going this fast."  It's a realtime measurement each vessel has on board.  You're grasping trying to  explain something that the FE model can't.


Edited to add:  I'll also throw this in here. The ACC is 20CM/S.  That's about .4 knots.  Ocean current velocity would be neglible with regards to the boats' speeds.

https://oceancurrents.rsmas.miami.edu/southern/antarctic-cp.html
« Last Edit: December 15, 2020, 06:44:56 PM by WTF_Seriously »
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

Offline SteelyBob

  • *
  • Posts: 175
    • View Profile
Re: Vendée Globe
« Reply #15 on: December 15, 2020, 07:13:19 PM »
The amusing thing here is, of course, that the boats know their position either via GPS or other satellite-based navigation systems, or they might use more traditional methods such as taking sightings from celestial bodies to calculate latitude. Both of these things require the earth to be globe-shaped, as do the sources that Tom used to support his own arguments around wind and current flows.

*

Offline RonJ

  • *
  • Posts: 1384
  • ACTA NON VERBA
    • View Profile
Re: Vendée Globe
« Reply #16 on: December 15, 2020, 07:19:45 PM »
Boats have two speeds.  Speed thru the water (STW) and speed over the ground (SOG).  Professional mariners know the difference and both are important in depending on the situation.  The relevant speed here is speed over ground.  That can be measured in several different manners, depending upon the situation.  If you can't get a fix relative to land because you are too far out, or are maybe in some fog, you have to depend upon GPS.  If you don't believe in GPS then you can use celestial navigation for a reasonably accurate position fix.  Then its a matter of determining the distance between two fixes and dividing by the amount of time that's passed.  Then you have an accurate speed and distance.  Aircraft pilots do the same thing.  Yes, the airspeed indicator gives just a ball park estimate of the ground speed but gives no indication of the headwind or tail wind component.  That can be determined by using accurate fixes relative to the ground, measuring the distance traveled and dividing by the time it took between the fixes.  When you compare that with the indicated airspeed you will have an idea of what kind of head or tail wind component is affecting the aircraft's ground speed. Over the ground speeds on both aircraft and boats can vary continuously because of the operational environment.  You can accurately make time and distance measurements and the resulting average speed measurement will then be accurate as well.   
For FE no explanation is possible, for RE no explanation is necessary.

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #17 on: December 15, 2020, 07:20:14 PM »
The amusing thing here is, of course, that the boats know their position either via GPS or other satellite-based navigation systems, or they might use more traditional methods such as taking sightings from celestial bodies to calculate latitude. Both of these things require the earth to be globe-shaped, as do the sources that Tom used to support his own arguments around wind and current flows.

Satellite data is extremely important for anyone racing.  That data supplies wind speeds all over the ocean and you can watch the boats change course in order to head to the locations of the highest wind velocities.  It's been quite fun to track.
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

Offline WTF_Seriously

  • *
  • Posts: 149
  • Sorry folks. The Earth is round
    • View Profile
Re: Vendée Globe
« Reply #18 on: December 15, 2020, 07:22:35 PM »
Boats have two speeds.  Speed thru the water (STW) and speed over the ground (SOG).  Professional mariners know the difference and both are important in depending on the situation.  The relevant speed here is speed over ground.  That can be measured in several different manners, depending upon the situation.  If you can't get a fix relative to land because you are too far out, or are maybe in some fog, you have to depend upon GPS.  If you don't believe in GPS then you can use celestial navigation for a reasonably accurate position fix.  Then its a matter of determining the distance between two fixes and dividing by the amount of time that's passed.  Then you have an accurate speed and distance.  Aircraft pilots do the same thing.  Yes, the airspeed indicator gives just a ball park estimate of the ground speed but gives no indication of the headwind or tail wind component.  That can be determined by using accurate fixes relative to the ground, measuring the distance traveled and dividing by the time it took between the fixes.  When you compare that with the indicated airspeed you will have an idea of what kind of head or tail wind component is affecting the aircraft's ground speed. Over the ground speeds on both aircraft and boats can vary continuously because of the operational environment.  You can accurately make time and distance measurements and the resulting average speed measurement will then be accurate as well.

Was hoping you'd give some input given your familiarity with ocean navigation.  I'm absolutely not a mariner in any way shape or form.  Simply making some observations.
Lol "Everyone is Wrong and LiEeInG"
That is a desperate argument from a losing position. An argument from a position of strength would have positive evidence for that position.

Re: Vendée Globe
« Reply #19 on: December 15, 2020, 07:42:51 PM »
The formula for speed is Speed = Distance / Time

If the distance is in question, then the speed is also in question.

The situation is fluids traveling within fluids. The winds and water are in motion. On board airplane airspeed indicators are similarly unreliable, and are not used for navigation. The local area of the airplane might be in motion faster than a larger area around that airplane, which might itself be in motion.


This is a joke, right?  Apart from their vital use at the lower end of the range, around stalling speed, this is the main reason for having an airspeed indicator.  I don't know when or where you did your own pilot training, but when I was taking lessons (in 1973) the first piece of kit I had buy was something called a "computer", which was a type of circular sliderule, where you would factor in your airspeed, intended course, and wind velocity and it worked out the heading you needed to steer.  En route, similar inputs would tell you how far you had travelled.  This is why commercial aircraft and large military aircraft carried navigators.  The windspeeds are forecast by meteorological agencies, and verified by shore stations and weather balloons. 

The advent of more advanced terrestrial navaids in the 50s, and GPS in the 90s has reduced dependence on dead reckoning, and consequently reduced crewing requirements, but its still a vital part of crew training.  Its also how Amy Johnson, Jim Molinson, Alan Cobham and thousands of other civilian pioneers and military pilots managed to find their way around the South Pacific in the 30s and 40s.

And I'd be very surprised if the Vendee sailors aren't comparing at least 3 different forms of navigation. 

(Incidentally, leading boat currently has a windspeed of 23 kts, to the rear of the peloton its around 8 kts.  Scary stuff).