• An ahistorically powerful and advanced Aztec civilisation, anno late 1400s.
  • A set of circumstances much like the ones that led Columbus west: one mad Aztec convinced the world was rather small and he could reach their trading partners (the Chinese) by sailing eastwards.

He sets sail from Haiti, the latest Aztec tributary. The season is undetermined. He has no knowledge of what he'll find on the other side, other than vague records of mythical place called Hindustan.

Where will he land?

Ship facts:

  • It's built for mainly the Gulf of Mexico, Caribbean sea and coastal waters from Georgia to Venezuela, but large enough to carry lots of tribute - which they now fill with supplies for the journey instead. Think a slightly smaller, Mesoamerican version of Zheng He's famous treasure ship.
  • There's at least one person aboard who's acquainted with oceanic travel (a Chinese defector - who in this reality regularly crossed the Pacific). The crew at large makes up for their lack of expertise in spirit though.
  • They do not have a clue what's on the other side of the Atlantic; their goal is to reach China. They do not know any currents that only reveal themselves far past the shores. They are going to have to discover all those things on the way east.

Sea facts:

Both the prevailing winds and the ocean currents (gyres) suggest a somewhat northerly course to be "ideal"; going parallel to the North American coast for a bit and ending up in Europe.

But if you look at Columbus' travels, and specifically the return trips, only on his first journey does he curve northward significantly before heading east, and it looks like he was specifically aiming for the Azores that time. So it is definitely not against the laws of physics to sail a straight eastbound path, which would have our brave Aztec land in Cape Verde or Mauritania.

So I wonder if there's an argument to be made that given a sailor with a suitable vessel but little knowledge of the deep ocean (just like Columbus) and no known destination to aim for, that a spot on the Atlantic coast from Senegal to Portugal is most likely to be hit?

Or are those prevailing winds/currents so strong and noticeable that any reasonable sailor encountering them for the first time would be compelled to adopt a more northerly course, and end up somewhere between Tanger and Scotland?

Or is it all so dependent on the season and weather conditions of the time that any destination between those northern and southern extremes is at least plausible?


So I did some more research and I made a map.


Fat arrows are winds, thinner arrows are ocean streams (of which the equatorial counter-current is only active in the late summer and autumn, apparently). The lines are all the west-east Atlantic crossings I could find the routes and dates for; just Columbus' four journeys. Don't really know where else to look.

It's... not that helpful in the end. Columbus crossed the Atlantic in basically every season, and he only followed the currents or winds twice.

Safe to say that I'm starting to lean towards any landing site for my Nahuatls to be plausible. If Columbus could take those routes in spite of wind and currents, couldn't my expedition do the same?

  • $\begingroup$ Do they have a compass? That is what Columbus used to go east and west. He used dead reckoning which is navigating by course and distance (estimated from speed). $\endgroup$ Commented Mar 29, 2020 at 22:14
  • $\begingroup$ @VilleNiemi good question; I am going to say yes, because the Chinese did. $\endgroup$
    – KeizerHarm
    Commented Mar 29, 2020 at 22:51
  • $\begingroup$ I would like to question one statement in your question. You write that the aztecs want to travel to their chinese trading partners. If they would have chinese travel partners, their whole culture would be affected by that. And they propably would have some rudimentary maps of asia, europe and africa - so it would be not at all like columbus trips. Wouldn't it be much easier to remove that statement and add some simple curiosity instead? $\endgroup$ Commented Mar 29, 2020 at 23:51
  • $\begingroup$ I meant east. They should go straight to the east based on the compass. Forgot the directions are reversed. But anyway if you want to go east and you have device that tells where east is that is where you will go. The problem with following the wind or currents that if you want to get back home the directions are reversed. If you are lucky that is. Some of the winds might be seasonal and you'll just get lost instead of running out of food and water. Just using the directions from the compass is much much more likely to see you return home. $\endgroup$ Commented Mar 30, 2020 at 2:22
  • $\begingroup$ @VilleNiemi its not like they cant use star as a guide as far as i know aztec has good astronomy, also chinese compass is pointing south though as far as i know so maybe that can also affect the direction. $\endgroup$
    – Li Jun
    Commented Mar 30, 2020 at 5:55

5 Answers 5


They would sail straight east and end up on the coast of Africa between Cape Verde and the Canary Islands.

They do not know the winds, the currents, or the geography on the other side. And more importantly, most importantly for your question, they know the do not know. They have no specific goal they can aim for.

With the navigation available to them this means they can only sail along the coast, north or south to reach a latitude, or east or west along the latitude. Sailing east along the latitude of their origin is the only one of these options that is useful for the initial crossing towards the old world.

You'll note that when Columbus went to Americas he first sailed to the Canary Island the westernmost Spanish holding and then sailed straight west along the latitude. On his return trip he went first north then north-east until he reached the latitude of his destination then straight east.

Later trips when he was more confident on the distances and had specific goals in the new world the routes become more precise and less angular because he, and your Aztecs, would have fair ability to estimate the distances sailed.

You cannot do this on the first trip over so it is not really relevant to the question but it is useful to note that on his first return trip Columbus was already confident he can sail north-east part of the way and that on his second return he already hits Spanish territory instead of Portugal. And felt confident to cross to west south of his initial trip to more or less continue his exploration where it ended on the first trip. (And knew which direction to go when he found islands.)

If you want them to sail straight to Europe.

Have the trade from China come via Japan and let your Aztecs know its latitude but nothing else about the geography. They would then start by sailing north along the coast to that latitude, then sail straight east. They'd probably end up somewhere in Iberia or France in this scenario.

And obviously knowing or guessing the latitude of part of China or Korea on that same latitude is just as good and Japan is just an example. I have no idea what port the Chinese would use.

  • 1
    $\begingroup$ After some pondering I think this is the most correct answer; unless if the vessel in question is for some reason hugely dependent on following the current/wind (more so than Columbus' ships), they would have to be aiming for something, and reaching that would be more important than taking the most efficient route which for all they know could be leading them in circles. $\endgroup$
    – KeizerHarm
    Commented Apr 6, 2020 at 20:45

The north-northeastern route would probably be the easiest, especially if we're assuming the ship's navigators are roughly as skilled as those on the Santa Maria, et al. This would take the ship, ultimately, to either the Iberian peninsula, or the British Isles, depending on whether the ship ended up following the Canary or Norwegian current, respectively. However, this also puts the ship at the mercy of North Atlantic storms, which, given the Aztec's unfamiliarity with such weather, might be a serious problem for the mariners (this is assuming the Aztecs haven't expanded further north than, say, the Carolinas, which seems unlikely given that Haiti is their newest tributary). Depending on the time of year they set sail, it's a roll of the dice whether they land at all.

However, there is a safer, and potentially more lucrative option (though the mariners wouldn't know it when they set out), it just requires a little more navigational acumen and seamanship. Polynesians sailors developed a method of sailing in which they would actually sail against the prevailing winds and currents, which meant that if they became lost, they could just grab the prevailing winds and sail back where they'd come from, almost like a kind of navigational save point. If your Aztecs developed this technique (maybe they got as far south as Peru, either conquering or trading with the Incas, and learned the technique from Polynesian sailors there), then they could sail "backwards" along the Atlantic North Equatorial Current, and end up in west Africa. Now, circa 1492, this brings them to the west African shores right around the time that the Songhai Empire is reaching its height. This could introduce your Aztecs to the pan-Islamic trade network, which would, in this writer's opinion, be of far more economic and cultural value to them than introduction to European Christendom circa 1492.

  • 2
    $\begingroup$ Thanks for the answer. A quick Google reveals that the storms you mention are most frequent in the autumn, so assuming a three month journey, if I want them to survive the trip, the Aztec expedition ought to have departed somewhere between November and April, arriving between February and July, right? The African route also sounds like a great idea, but for their eventual European landing (they're going to do this multiple times) the date seems to matter. $\endgroup$
    – KeizerHarm
    Commented Mar 30, 2020 at 22:03
  • $\begingroup$ And also; are those prevailing winds and currents noticeable enough for a crew who have never been to the deep Atlantic before? Like, I do not know much about navigation, but could someone tell, in the middle of the ocean: "Right, we're not going anywhere at this rate, let's go northeast instead of straight east"? $\endgroup$
    – KeizerHarm
    Commented Mar 30, 2020 at 22:21
  • 2
    $\begingroup$ @KeizerHarm From what I understand, the prevailing winds are pretty much impossible to miss, simply because the crew would notice that the winds are, on average, always blowing in the same direction. I suppose how quickly they catch on would depend on how long your Aztecs have been engaged in mid-distance sailing: the Spanish and English had decently-long maritime traditions before the first Columbian voyage, ditto China with Zheng He. If this is their first real outing, there might be a much longer learning curve. How long exactly, I can't say with confidence, unfortunately. $\endgroup$ Commented Mar 30, 2020 at 22:28
  • $\begingroup$ Right, so I suppose their expedition would have greater odds of success if they had already discovered Bermuda, to function as their Azores-analogue for practise and exploration. That in turn does sort of predispose a European landing, I'm afraid. $\endgroup$
    – KeizerHarm
    Commented Mar 30, 2020 at 22:31
  • 1
    $\begingroup$ Do you have a reference for "Polynesians sailors developed a method of sailing in which they would actually sail against the prevailing winds and currents, " It would be interesting to see how close they could sail into the wind. $\endgroup$
    – DrMcCleod
    Commented Mar 31, 2020 at 15:14

First of all Columbus knew where he is aiming for. Or at least he knew how the sky should look like there. All he needed was to close the sky map of stars. So that's why the first travel TO was in a rather straight line. They had to keep some sort of regularity while charting. So they used Sun as a reference point.
During their way back and other ones they have a rather good idea of what they need to look for in the sky to get back in both directions and that they have enouch "anchor" points to get to place where they want to land.

The thing is that distance from China to Americas is much greater than from South America (especially from Rio Grande Do norte) to Europe or Africa. A seasoned (or just knowledgeable) sailor should know about equatorial countercurrent. And they could try to find exactly the same thing on the other side of America. Landing in african congo Basin Area. They would also prepare for a much longer voyage then it would really be needed. Again, because the distance on Pacific is much greter than on Atlantic.

Also remeber that Columbus knew where he wanted to land in China/India. You have two set points, you have refrence (sun) and you have, let's say assumed knolwedge of 75% of sky above you. You know the earth is round. So you make the route the way you want.

  • $\begingroup$ But if Columbus could look at the stars and find out his location, and he knew what the stars looked like in the East Indies, then shouldn't he, during his journey, have started to notice that he wasn't getting anywhere close to his destination in their travel time? If the Americas hadn't existed, he and his crew would have starved long before reaching it. And then he did land in America and thought it was part of Indonesia until his deathbed; what could he have been aiming for exactly, with how much confidence? $\endgroup$
    – KeizerHarm
    Commented Apr 2, 2020 at 12:40
  • $\begingroup$ Just to be clear, I appreciate your other thoughts, like that the expedition would be supplied for a Pacific journey; I just have questions about the extent to which Columbus knew what he was aiming for. $\endgroup$
    – KeizerHarm
    Commented Apr 2, 2020 at 12:53
  • 1
    $\begingroup$ They knew that they don't know a part of the sky. The amount of gap was, probably, eye balled as we know his food reserve wan't enough cross, what we now know, as pacific ocean. He wanted to land somewhere in China, Japan or Molouki Islands. So anwyhere beetwen equator and Japan. A distance relating to one beetwen Porto and Senegal. So I assume your chinese sailor would also try to aim for that "left" part of China he knows. If you cut out americas from maps and fold it into a cylidner you will notice that Columbus would land in Molouki Island vicinity. $\endgroup$ Commented Apr 2, 2020 at 12:56
  • $\begingroup$ Alright, I suppose that makes sense. Thank you for your thoughts; using the equatorial countercurrent to get to Congo is already a wildly different outcome from what I had coonsidered! Once I have time I think I'll make a map of possible routes, taking this information into account. $\endgroup$
    – KeizerHarm
    Commented Apr 2, 2020 at 13:35

Until the Atlantic currents were understood (well after regular trading voyages were set up between Europe and the Americas), Captains would just try to set a course to their destination and then use the winds as they could to get there.

Eventually it was noticed that voyages going to America across the northern Atlantic would take considerably longer than those on a more southern course.

So courses that are going against the currents are not impossible, but they will make the voyage much longer.


If we are talking wind-driven ships I would most definitely recommend a somewhat north-heavy route leading to somewhere between Ireland and northern Portugal. It is technically possible to go east directly from Haiti, but I don't think it reasonable to oppose both wind and water currents for no real reason, any sane sailor would understand that following those would bring you forward much faster.


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