Speaker 1: Hey you welcome to Stuff to Blow Your Mind. This
Speaker 1: is Robert Lamb and this is Joe McCormick, and today
Speaker 1: we have an episode from the vault for you. This
Speaker 1: is part two of our series on Pacific Island navigation.
Speaker 1: This episode originally aired July. Let's dive right in Welcome
Speaker 1: to Stuff to Blow Your Mind production of My Heart Radio. Hey,
Speaker 1: welcome to Stuff to Blow Your Mind. My name is
Speaker 1: Robert Lamb and I'm Joe McCormick, and we're back with
Speaker 1: part two. In the last episode, we talked about the settlement,
Speaker 1: the original colonization of the Pacific Islands, and today we're
Speaker 1: back to talk about some documentation of the amazing navigation
Speaker 1: techniques used by the master navigators of various Pacific islands.
Speaker 1: And I'm really excited to talk about this stuff today
Speaker 1: because I've been reading this big, very important book on
Speaker 1: the subject that was published in nineteen seventy two by
Speaker 1: an author named David Lewis, called We the Navigators that
Speaker 1: involves extensive interviews with and then direct sailing and firsthand
Speaker 1: observation of the navigation techniques of master navigators from the
Speaker 1: Pacific Islands. For example, a man named Tevak of the
Speaker 1: Santa Cruz Reef Islands and a man named hip Or
Speaker 1: of Poula Watt in the Carolines. And today we're gonna
Speaker 1: be talking about some of these specific navigation techniques. Yeah,
Speaker 1: and again these are the techniques of environmental navigation, so
Speaker 1: navigation at sea on the open sea, conducted without instruments.
Speaker 1: And so I mean that's ultimately the really amazing part
Speaker 1: of this. But then at the same same time, I
Speaker 1: want to stress something we've mentioned in the first episode
Speaker 1: that this is also not based in sort of a
Speaker 1: gut instinct, a kind of well I've been at sea enough,
Speaker 1: I kind of know what I'm doing. No, this is
Speaker 1: a this is a science. This is this is these
Speaker 1: are techniques that would have that were passed down from
Speaker 1: generation to generation, from skilled individual to two skilled individual.
Speaker 1: And uh and so you know, we see this continued
Speaker 1: on in oral traditions, but then also we've seen them recorded,
Speaker 1: especially in the last few decades. Uh, that there's been
Speaker 1: a resurgence of interest in this um an effort to
Speaker 1: to make sure that these traditions and techniques survived and
Speaker 1: then also to use them to understand the history of
Speaker 1: the colonization of these islands by ancient humans, right. And
Speaker 1: one of the points that Lewis argues in his book
Speaker 1: is that the colonization of the islands of the Pacific
Speaker 1: was not driven entirely by random drift, say, people getting
Speaker 1: blown off course by a storm or getting lost and
Speaker 1: then happening upon a new island. That that Instead, he
Speaker 1: argues that a lot of these islands were probably discovered
Speaker 1: by deliberate exploratory probes. Right, So let's get into some
Speaker 1: of the techniques. Then We're going to start with what
Speaker 1: may seem the most obvious, and that is the stars.
Speaker 1: There are a lot of amazing techniques to talk about,
Speaker 1: but this is by far the most important one. Yes,
Speaker 1: So Pacific islanders, uh, specifically, the trained navigators, they did
Speaker 1: use the stars. The train navigator knew the positions of
Speaker 1: important stars and their relationship to islands by heart. They
Speaker 1: knew how the pattern of the stars changed depending on
Speaker 1: where you went and what time of the year it was.
Speaker 1: And they could also use the stars to determine latitude,
Speaker 1: so that's her north south positioning. They could roughly determine
Speaker 1: where they were in relation to the equator based on
Speaker 1: the height of polaris or the southern cross above the horizon,
Speaker 1: which they would measure, again not using instruments, but using
Speaker 1: the human hand. Yes, or sometimes I think also maybe uh,
Speaker 1: parts of the boat could be used to sort of
Speaker 1: orient with the stars on the horizon. So if you're
Speaker 1: unfamiliar with this kind of technique, as obviously most of
Speaker 1: us are as I am, the mind is immediately boggled.
Speaker 1: Right you think, Okay, how would I use the stars
Speaker 1: to find I don't know, a city or something like that. Uh,
Speaker 1: you don't. You wouldn't even know where to start. But
Speaker 1: once you know what to look for, this actually becomes
Speaker 1: an extremely reliable method. Uh, And specifically the really important
Speaker 1: guide stars here are constellations that are low in the
Speaker 1: sky around the point where they are either rising or setting,
Speaker 1: and can be easily associated with a particular heading toward
Speaker 1: the horizon. So you're steering your boat and you're observing
Speaker 1: the stars right around the horizon. So these would be
Speaker 1: either stars and star constellations that have recently risen or
Speaker 1: are about to set, depending on which direction east west
Speaker 1: you're heading. So if you have a particular destination in mind,
Speaker 1: and you know you're starting position, you can associate your
Speaker 1: destination with a particular guide star, or what a guide
Speaker 1: star would actually mean is a series of stars and
Speaker 1: star constellations that will move move vertically up and down
Speaker 1: across the sky as the night goes on. But they
Speaker 1: might be identified by say the first star you would
Speaker 1: see in the sequence, as as the guide star, and
Speaker 1: then the train of subsequent stars that would move up
Speaker 1: and down as the night goes on. But that is
Speaker 1: associated with a particular island. Now, of course, it gets
Speaker 1: much more complicated than that, because, for one thing, you
Speaker 1: have to take into account position and geography. Because while
Speaker 1: a star can help give you a heading toward a
Speaker 1: known island that's associated with it would only necessarily be
Speaker 1: associated with the island you're heading for from a particular direction. Right,
Speaker 1: So if you're heading from east to west, the island
Speaker 1: you're looking for is under a certain star, but if
Speaker 1: you're heading from north to the same island, that island
Speaker 1: would be under a different star. Right. So the stars
Speaker 1: help you get an orientation, but you have to know
Speaker 1: the relationships between a sort of mental map of islands
Speaker 1: in your head and how shifting the starting point of
Speaker 1: the journey will shift, what star path will lead you
Speaker 1: to your island destination. But it gets even more complicated
Speaker 1: than that, because, of course, as we mentioned, the stars
Speaker 1: don't stay still throughout the night. The earth is rotating,
Speaker 1: so the fixed stars rise and set across the sky
Speaker 1: over the course of a night. And as the stars
Speaker 1: rise higher or set below the horizon, they become less
Speaker 1: useful or not useful at all for navigating without equipment
Speaker 1: and charts, not just because say, they're higher as they're
Speaker 1: rising up, but also because they tend to rise at
Speaker 1: an angle, so they won't stay right where they're supposed
Speaker 1: to be on the horizon. What you want is a
Speaker 1: reference star that is either just rising if you're heading east,
Speaker 1: or is just about to set if your head west. Um,
Speaker 1: So what do you do there? Well, what you would
Speaker 1: tend to do is cycle through new sets of rising
Speaker 1: or falling guide stars that you know will keep you
Speaker 1: pointed in the right direction. And Lewis writes about this
Speaker 1: that on average you won't need more than about ten
Speaker 1: guide stars to sail through an entire night, given the
Speaker 1: amount of time that each star is usually pretty close
Speaker 1: to the horizon, close enough to be usable. So you
Speaker 1: can almost imagine kind of a I don't know, like
Speaker 1: those like stock ticker strips. You know, the old one
Speaker 1: is like a strip of stars that are peeling up
Speaker 1: over the horizon all night long, and each one, you know,
Speaker 1: is the next one in the set that is still
Speaker 1: oriented with the top star in that strip that will
Speaker 1: keep you going in the direction you need to go.
Speaker 1: But stop and think about, like how much memorization this requires,
Speaker 1: Like how much you need to know about what the
Speaker 1: stars look like, what their orientations are, and their relationships
Speaker 1: to the islands you need to get to depending on
Speaker 1: where you're starting point is So the amount of now
Speaker 1: vigational lore that needs to be committed to memory and
Speaker 1: the amount of detail in it is is absolutely astounding.
Speaker 1: I mean, it reminds me a little. These are not
Speaker 1: directly comparable at all, but it reminds me a little
Speaker 1: of how in or was it Mark Twain's life on
Speaker 1: the Mississippi talking about how an experienced riverboat pilot would
Speaker 1: need to know by heart the entire river, like all
Speaker 1: the various details of its its twist and binds, its depth, etcetera,
Speaker 1: and everything that went into knowing it. Which, um, yeah,
Speaker 1: from what I've read, you can you can basically take
Speaker 1: that and apply it to to any kind of nautical setting.
Speaker 1: And certainly this one is well like you would need
Speaker 1: to to know by heart the environment through which you
Speaker 1: would be uh sailing, the environment of the waters, but
Speaker 1: also the environment of the stars above. Yeah. And it
Speaker 1: seems that while I don't know, while the mental memorization
Speaker 1: of physical surroundings on land, including like trees and changes
Speaker 1: in terrain and rocks and landmarks and stuff like that,
Speaker 1: it maybe this is just my land lubber bias, but
Speaker 1: it it seems like that kind of thing probably comes
Speaker 1: more intuitively. It's more just sort of like a biological
Speaker 1: default to recognize landmarks like plants and rocks and stuff
Speaker 1: like that. Then it would be to memorize the stars
Speaker 1: as your landmarks for guidance. Yeah, yeah, I think you're right.
Speaker 1: I mean, it almost feels like saving through through space. Uh,
Speaker 1: though of course there's gonna be plenty concerning the water
Speaker 1: itself and uh and uh and other environmental cues that
Speaker 1: will get to But but certainly at this point in
Speaker 1: the in the podcast, it's easy to to almost think
Speaker 1: of these as space voyages because of the degree of
Speaker 1: focus that must be placed on the stars, right, and
Speaker 1: so experienced specific navigators can use these rising and setting
Speaker 1: guide stars to form this extremely accurate mental compass. Lewis
Speaker 1: gives one example of one of his voyages with the
Speaker 1: navigator TVAK, and he says, quote, by these obliquely sinking stars,
Speaker 1: he was able to inform me that during the evening
Speaker 1: that the wind had backed from southeast to south southeast.
Speaker 1: I seriously doubted the accuracy of his observation until Canopus,
Speaker 1: topping the horizon on a bearing of a hundred and
Speaker 1: forty three degrees exactly in line with our stern, confirmed
Speaker 1: that we were in fact dead on course and that
Speaker 1: the wind had changed. Now, there's another variation on the
Speaker 1: idea of guide stars for navigation that is known as
Speaker 1: the sidereal compass. That is basically like a view of
Speaker 1: the night sky that identifies particular rising or setting stars
Speaker 1: with points on an imagined compass. Again, this is not
Speaker 1: a piece of equipment and external tool. This is a
Speaker 1: compass in the brain that has a picture a mental
Speaker 1: map of the stars and how the stars along the
Speaker 1: horizon will give you information about north, southeast, and west. Now,
Speaker 1: these are the basic primary methods of navigation by stars,
Speaker 1: but obviously in practice, it's a lot more complicated, so
Speaker 1: a few examples. Of course, there is a lot of
Speaker 1: adjusting the course to compensate for variations in currents and winds,
Speaker 1: and to be adaptable for for celestial orientation markers when
Speaker 1: part of the sky is obscured, for example, by clouds,
Speaker 1: and I'll mention more about that in a minute. There's
Speaker 1: another thing that's a complication with the use of guide
Speaker 1: stars for navigation, which is the seasonality of guide stars. Now,
Speaker 1: of course, the availability of guide stars varies with the seasons,
Speaker 1: because the sidereal day is actually twenty three hours and
Speaker 1: fifty six minutes long, not twenty four hours. So each
Speaker 1: star rises and sets four minutes earlier each night. And
Speaker 1: as you can imagine, as this builds up over time,
Speaker 1: you're actually going to be having different star maps available
Speaker 1: to you as the year goes on. So in illustrating this,
Speaker 1: Lewis writes that quote Tevak told me that the sailing
Speaker 1: season in the Santa Cruz group lasted all year round,
Speaker 1: and that there were appropriate steering stars for each time
Speaker 1: of year. Similarly, when two two indicated the stars for
Speaker 1: the Nomuka Tonga Tapoo passage, he stressed that the ones
Speaker 1: he was showing me were usable only up to about September,
Speaker 1: after which new stars and sailing directions had to be used.
Speaker 1: So not only do you have to understand this whole
Speaker 1: star map and its relationship to the island geography, but
Speaker 1: also if you if you're sailing across different seasons, you
Speaker 1: have to have the seasonal backups in mind as well.
Speaker 1: Then there's even more to to take into account. One thing,
Speaker 1: for example, is wind and leeway, So experience navigators will
Speaker 1: have a mental map to reach their destination that must
Speaker 1: include compensation for leeway, you know, the sideward drift of
Speaker 1: a boat as as is blown sort of off course
Speaker 1: by wind. So if the navigator knows that the destination
Speaker 1: is under a particular star, but there is a known
Speaker 1: and relatively dependable amount of southerly drift on the journey
Speaker 1: do to prevailing winds and currents, they actually have to
Speaker 1: aim a certain amount north of the guide star. Yeah,
Speaker 1: and that's just for permanent drifts. There's also sort of
Speaker 1: more ad hoc compensation that has to take place along
Speaker 1: the way as well. But one of the big things
Speaker 1: that that really struck me about this was how how
Speaker 1: much it inverts the logic of nighttime navigation versus daytime navigation.
Speaker 1: You know, uh, like, how how would you think, what
Speaker 1: do you think would be the best time to try
Speaker 1: to get somewhere. Obviously you would probably think it's in
Speaker 1: the day right when you can see where you need
Speaker 1: to go. But it is much easier to use the
Speaker 1: highly dependable celestial navigation techniques of of the Pacific Islander
Speaker 1: navigation lore at night than it is in the daytime.
Speaker 1: There there's still tools they use in the daytime, and
Speaker 1: I'll talk about those in a minute. Um, But even
Speaker 1: when the stars are largely obscured by clouds and experience,
Speaker 1: navigator can usually use some stars in the sky to
Speaker 1: orient and to get onto the correct bearing, for example,
Speaker 1: by noting which stars might lie it's a nine d
Speaker 1: degrees to the course, etcetera. Yeah, I mean it almost
Speaker 1: sounds like you would you would probably want to leave
Speaker 1: the shore, you know, around dusk, um, and uh, and
Speaker 1: then once and then hopefully you're you're out to sea
Speaker 1: by the time the stars have come out. Right. Well,
Speaker 1: there's actually there's a good bit of thought about when
Speaker 1: are the best times to arrive and depart. So they
Speaker 1: talked about Yeah, I think it's usually customary to leave
Speaker 1: during the daytime. And one of the main reasons it's
Speaker 1: important to leave during the daytime is not only that
Speaker 1: people can be notified and you can say prepare things
Speaker 1: to take along with you that same day, like fresh food,
Speaker 1: and you can say your farewells to people during the daytime,
Speaker 1: but you can also look back at the island you're
Speaker 1: leaving from to get back bearings, right, so you can
Speaker 1: make use of the land if your navigation for as
Speaker 1: long as it's feasible, right. And it's also usually can
Speaker 1: cosidered important to arrive at your destination during the daytime
Speaker 1: because one of the great perils actually of Pacific navigation
Speaker 1: is accidentally missing your target in the dark. If you
Speaker 1: sail past the island in the dark and you don't
Speaker 1: realize you've done it, that can be uh that that
Speaker 1: could be a death sentence. So it's kind of interesting
Speaker 1: while you're out on the open ocean, navigating at night
Speaker 1: is ideal. That's you know, where you get these accurate
Speaker 1: guide stars. But I think it's often considered good to
Speaker 1: leave the island during the daytime and to arrive at
Speaker 1: your destination during the daytime. And sometimes uh. And there
Speaker 1: might be some exceptions to that, but those seem to
Speaker 1: be some general principles that were observed at least that
Speaker 1: Lewis mentioned and uh. And so that would require very
Speaker 1: careful timing of the journey, right, Like you need to
Speaker 1: know pretty much exactly how long it's going to take,
Speaker 1: how many days, so that you can time it out
Speaker 1: like that. And just as one example about the dangers
Speaker 1: of missing an island at night, uh, the Lewis talk
Speaker 1: about at least one of the navigators he worked with
Speaker 1: having a practice of when you're getting close to the
Speaker 1: island and it's really dark out, sometimes they would just
Speaker 1: stop sailing. They would slow down. They would uh it's
Speaker 1: called heaving to you know, they would heave to to
Speaker 1: slow the progress of the boat, just to be super
Speaker 1: careful that they didn't accidentally, say, sail between two islands
Speaker 1: unnoticed in the middle of the night. But while the
Speaker 1: nighttime star navigation is the most accurate thing to use,
Speaker 1: there are clues you can use for navigation in the
Speaker 1: daytime as well. For example, you can use the sun.
Speaker 1: It's more difficult to use the sun, but it can
Speaker 1: be done. Uh. And it's more difficult for a number
Speaker 1: of reasons. First of all, there's only one of it,
Speaker 1: and its position can vary a lot over the seasons. Right,
Speaker 1: Unlike the stars, the relative position of the Sun on
Speaker 1: the horizon of Earth has a lot more variability. But
Speaker 1: even with the seasonal variability of the Sun's position, you
Speaker 1: can still use it to navigate by pairing it with
Speaker 1: external reference to the stars. And this was one of
Speaker 1: the many moments in this book. It gave me that like, oh,
Speaker 1: of course kind of feeling, and this was one of them.
Speaker 1: So uh So, Lewis writes at one point about another
Speaker 1: scholar who had been writing about Pacific navigation uh named
Speaker 1: acre Blom. He says, quote acre Blom surprisingly asserts that
Speaker 1: to achieve a satisfactory degree of accuracy when checking the
Speaker 1: course by means of the bearing of the rising or
Speaker 1: setting sun, the Polynesian navigator must necessarily have had access
Speaker 1: to some form of memorized table of the changes in
Speaker 1: the sun's asimuth. So it's you know, changes in rising
Speaker 1: and setting patterns over the seasons. But contrary to that,
Speaker 1: Lewis says, all the navigator actually needs, of course, are
Speaker 1: his eyes and a knowledge of the stars. The sun
Speaker 1: star comparison could be made twice in each day if
Speaker 1: one were so minded. So when the sun is rising
Speaker 1: or setting, you can check its orientation with respect to
Speaker 1: the stars that appear, you know, before or after it,
Speaker 1: and then you can basically know where on the horizon
Speaker 1: it is rising or setting at this time of er. Wow. Yeah.
Speaker 1: Now there are other methods of maintaining course setting during
Speaker 1: the daytime that are again more difficult than the nighttime,
Speaker 1: but still possible. And another method that I thought was
Speaker 1: really interesting was steering by ocean swells. And there are
Speaker 1: actually two different uses here. Um, So there's one thing,
Speaker 1: which is navigation by swells in the open water. So
Speaker 1: if you're out you know no side of land anywhere nearby,
Speaker 1: you can use ocean swells to help you do direction finding,
Speaker 1: just like you would use the sun or the stars.
Speaker 1: But in addition to that, using the swells is actually
Speaker 1: a land finding technique. It changes in how the ocean
Speaker 1: swells are affected by nearby land masses can be used
Speaker 1: to locate islands that are nearby, and this is something
Speaker 1: we'll probably talk about more in the next part of
Speaker 1: this of this series. But what does it mean to
Speaker 1: steer by swells in the daytime. Well swells are permanent
Speaker 1: wave patterns with specific cardinal origin points, which are associated
Speaker 1: not with waves kicked up by transient weather, but with
Speaker 1: strong and persistent wind patterns associated with specific permanent weather systems,
Speaker 1: for example, the trade winds or what or what A
Speaker 1: Louis calls the Southern Ocean belt of strong Westerly's. Yeah,
Speaker 1: and I think we can sort of loosely imagine like
Speaker 1: a recreation of a basic form of this, you know,
Speaker 1: some sort of a model or a simulation. If you
Speaker 1: had a body of water and you had say a
Speaker 1: fan or something creating some sort of you know, disturbance
Speaker 1: across the surface, and it it was regular, what would
Speaker 1: happen if you then dropped some islands in there? It
Speaker 1: could disrupt the waves, especially in if we were talking
Speaker 1: in in the actual ocean, in the form of long
Speaker 1: ocean waves as they bend around land masses, and and
Speaker 1: this wave disruption can be identified by a skilled eye
Speaker 1: enable them to detect land hundreds of kilometers wave and
Speaker 1: which is is pretty amazing, right, And so that's the
Speaker 1: kind that would be used specifically for the land finding, right,
Speaker 1: But you can also use the c swells, like you
Speaker 1: would use the stars to get directional orientation to know
Speaker 1: which direction is north southeast or west without a compass,
Speaker 1: because if you know basically what direction a c swell
Speaker 1: that is permanent and reliable comes from, you can detect
Speaker 1: that swell and then no, okay, that way is south southeast. Right.
Speaker 1: So so now we have not only the stars above,
Speaker 1: but also uh the wave patterns the CEA swells as well. Right,
Speaker 1: So these permanent weather patterns, they originate in a fairly
Speaker 1: consistent direction from your location. Now, part of the ignorant
Speaker 1: land dweller in me is just incredulous here, right, Like
Speaker 1: when I'm out in a boat on the ocean, waves
Speaker 1: seem utterly random to me. I could not I could
Speaker 1: not identify that waves are coming from a particular direction.
Speaker 1: And you know, but they're well, unless it's coming from
Speaker 1: a ski do right then you write motor boat that's coming.
Speaker 1: By then it's pretty clear what's creating the distraction. That's
Speaker 1: a good point. But you know, just the general choppy
Speaker 1: wave patterns of the ocean, I wouldn't have any idea
Speaker 1: what to do. But if you are trained in knowing
Speaker 1: what to look for, you actually can identify particular wave
Speaker 1: patterns or swell patterns. Lewis actually makes a distinction between
Speaker 1: waves and swells um but but they're not just random.
Speaker 1: The system of orientation based on swells is not as
Speaker 1: reliable as the stars, but it's still pretty reliable. So
Speaker 1: the question would be, well, how do you detect them?
Speaker 1: One interesting fact is that the navigators Lewis learned from
Speaker 1: seemed to consult the swells based on feeling them in
Speaker 1: the body more so than looking at them, which means
Speaker 1: that they can be used to steer not only in
Speaker 1: the daytime, but on overcast nights. So when the stars
Speaker 1: are completely hidden that's your main orientation tool gone, and
Speaker 1: there's no light to see, you could still potentially feel
Speaker 1: the directional swells and get an orientation based on that. Wow,
Speaker 1: that's interesting and it makes perfect sense. So how do
Speaker 1: you feel swells? Well, there's a part in Lewis's book
Speaker 1: where he talks about this. He says, quote T. K
Speaker 1: told me he would sometimes retire to the hut on
Speaker 1: his canoes out rigger platform, where he could lie down
Speaker 1: and without distraction, more readily direct the helmsman onto the
Speaker 1: proper course. By analyzing the role and pitch of the
Speaker 1: vessel as it cork screwed over the waves. In distinguishing swells,
Speaker 1: he stressed, you have to wait patiently until the one
Speaker 1: you want has a spell of being prominent and discernible.
Speaker 1: So there is a lot of noise in the waves, right,
Speaker 1: So there's a lot of conflicting, you know, wave wave
Speaker 1: action coming in different directions. But there's a certain pattern
Speaker 1: you can recognize from a known swell, And once there's
Speaker 1: a there's the right kind of timing in the wave
Speaker 1: action for you to IDENTI find the pattern of that
Speaker 1: known directional swell, you can orient based on that, and
Speaker 1: this would be again done by feeling it in the
Speaker 1: body and feeling the direction of the rolling of the boat.
Speaker 1: So when you think about how a boat moves in
Speaker 1: the waves, it can pitch, it can move up and down,
Speaker 1: forward to back, and it can roll from side to side,
Speaker 1: and the interaction of pitch and roll will tell you
Speaker 1: something about the direction that the swell is coming from.
Speaker 1: Right now, in saying that this type of navigation method
Speaker 1: is more reliable than it sounds, I also don't want
Speaker 1: to overstate or understate the difficulty of detecting it right
Speaker 1: that there is a lot of noisy way of action
Speaker 1: going on in the ocean, so somebody has to be
Speaker 1: really experienced and know what it is they're feeling for
Speaker 1: in order to feel it. And I just want to
Speaker 1: read one section of Lewis talking about attempting to understand
Speaker 1: what's going on with the navigation based on swells. Uh
Speaker 1: He writes, quote the course toward Tomaco was east northeat
Speaker 1: directly into the C swell that came from the same
Speaker 1: direction that it was only present or at any rate detectable.
Speaker 1: Occasionally at such times it could be picked out by I,
Speaker 1: and as the ship rowed up and over it, meaning
Speaker 1: pitched without any role at all, except when the steep
Speaker 1: northerly wind wave happened to coincide when the boat, the
Speaker 1: Spiorn was rolled to starboard at the same moment as
Speaker 1: she was pitching over the head on C swell. In
Speaker 1: those long intervals where the C swell was absent, the
Speaker 1: wind wave rolled us to starboard about once every five
Speaker 1: seconds without there being any pitching component. I could feel
Speaker 1: little effect from the southeast or northwest swells. After nightfall,
Speaker 1: we steered by the stars, the swells remaining unchanged except
Speaker 1: that the wind wave declined. So that's about like trying
Speaker 1: to understand that they're different. In fact, there are multiple
Speaker 1: swells at any given time, probably hitting you from different directions,
Speaker 1: and so the experience navigator is looking or a particular
Speaker 1: type of swell. You know that you could actually make
Speaker 1: the same journey potentially and look for different swells to
Speaker 1: steer you in aid of it. You just have to
Speaker 1: know which ones you're feeling for. And that goes back
Speaker 1: to the example you mentioned earlier about just like like
Speaker 1: setting there or laying there on the boat and just
Speaker 1: waiting to to feel the one you're looking for. It's
Speaker 1: not just okay, the waves you're hitting me, I got
Speaker 1: the pattern. No, you're looking for the specific pattern amid
Speaker 1: the noise or amid the waves right when there may
Speaker 1: be multiple patterns coming at you at the same time.
Speaker 1: You're just trying to pick the right one out, get
Speaker 1: the timing right to understand, yes, this is it. But
Speaker 1: as you were talking about earlier, I think it's important
Speaker 1: to remember and again, well we'll get more into this
Speaker 1: in the next episode. The ability to detect and measure
Speaker 1: swells in their direction of origin is not useful just
Speaker 1: in steering on the open ocean, but it's also one
Speaker 1: of the techniques for understanding when land is near. Now,
Speaker 1: there are a couple of other things that are really
Speaker 1: interesting about navig aiding on the open ocean. There's one
Speaker 1: more orientation technique that is even less reliable than the others,
Speaker 1: but it is sometimes still used as a backup. That's
Speaker 1: known as the wind compass. So it's it's basically operating
Speaker 1: on the presence of known wind patterns to give you
Speaker 1: indications about about directionality. So you might, for example, use
Speaker 1: the aid of a tool here, an external tool like
Speaker 1: a pennant, the you know, kind of flag object that
Speaker 1: would allow you to determine patterns of winds and where
Speaker 1: they come from. And if you know that there are
Speaker 1: certain dominant patterns of winds, you can kind of use
Speaker 1: that to give you another data point in orienting your
Speaker 1: boat in the right direction. Now, there's a whole other
Speaker 1: world of ad hoc adjustment that needs to take place
Speaker 1: on top of everything we've already been talking about. You know,
Speaker 1: basically everything we've been talking about is getting the correct bearing,
Speaker 1: knowing you're going in the right direction towards your target
Speaker 1: island based on your starting point. But of course in
Speaker 1: sailing you can always just sail in a straight line.
Speaker 1: Right winds and ocean currents will gradually shift you off
Speaker 1: course and you have to understand how that's happening and
Speaker 1: compensate for it. Which again this is one of those
Speaker 1: things where I just like react to that, thinking like
Speaker 1: it seems impossible, how could you do it? But but
Speaker 1: they have methods that they can do it. And there
Speaker 1: are a lot of methods here, but for example, one
Speaker 1: that I really liked, Lewis discusses on the first stage
Speaker 1: of one journey with hip Hoor, departing from pula Wat,
Speaker 1: hip Hoor would keep track of back bearings on the
Speaker 1: island that they were leaving to see how the current
Speaker 1: was affecting their heading. So you have the reference point
Speaker 1: of the island, landmarks the island you're leaving, and then
Speaker 1: you can see from your heading as you're leaving the
Speaker 1: island how strong the current is at the moment. And then,
Speaker 1: to to read from Louis here quote if said hip
Speaker 1: Hoor it turned out on further observation to be weak,
Speaker 1: we would head towards It's the point where vegas set,
Speaker 1: which is about at three hundred and nine degrees if strong,
Speaker 1: as proved to be the case towards the setting point
Speaker 1: of the pl A D s at about two hundred
Speaker 1: and eighty five degrees. Thus there were at least two
Speaker 1: distinct star courses traditionally laid down for this passage, and
Speaker 1: probably four to allow for strong and weak south flowing currents.
Speaker 1: This was a north flowing current. So not only do
Speaker 1: you need to know the right headings for uh, for
Speaker 1: the island you need to get to under you know,
Speaker 1: basically like neutral conditions, you also have to know what
Speaker 1: headings you would use if the current is a certain
Speaker 1: strength in a certain direction and the corresponding guide stars
Speaker 1: of course, um. But so if the wind or current
Speaker 1: is moving you laterally off course while steering in the
Speaker 1: open ocean, and so you don't have like, you know,
Speaker 1: back bearings like an island to refer to. How would
Speaker 1: you even know it? How do you know how far
Speaker 1: off course you're getting blown by the wind. This was
Speaker 1: another moment where the technique was revealed and was like, oh,
Speaker 1: of course, I thought this method was ingenious. Some of
Speaker 1: the navigators here would look at the wake left behind
Speaker 1: by the boat. So if if leeway I mean, you know,
Speaker 1: wind the blowing the boat sideways in addition to forward.
Speaker 1: If leeway is affecting your course, one way to judge
Speaker 1: this is by looking at the degree of the angle
Speaker 1: between the straight line you're attempting to steer on. So
Speaker 1: you can imagine a straight line going from the stern
Speaker 1: to the bow of the boat, you know, and just
Speaker 1: going off towards the horizon in every direction. Look at
Speaker 1: the angle between that line and the trail of wake
Speaker 1: left behind you. This might be kind of hard to
Speaker 1: visualize without a without a picture, so I'm sorry, but Rob,
Speaker 1: I've got a picture for you to look at. Here
Speaker 1: you can see that there's actually an angle of difference
Speaker 1: in between the wake behind the boat as you're getting
Speaker 1: blown off course and the straight line that you are
Speaker 1: attempting to steer on. Yeah, you can imagine it is
Speaker 1: looking back and saying, not a straight wake behind you
Speaker 1: going back to you know, to just directly behind you,
Speaker 1: as if it is a line drawn from the rear
Speaker 1: of the vessel, but something that is diagonal because because
Speaker 1: of the way the wind is blowing the vessel from
Speaker 1: the side right. So by seeing that angle and how
Speaker 1: large it is, a master navigator is able to correct
Speaker 1: for the amount of leeway that they're being blown off course.
Speaker 1: Now there's a huge thing that we haven't gotten into
Speaker 1: in detail yet here, but a big section of Lewis's
Speaker 1: book is about the Pacific navigation forms of dead reckoning,
Speaker 1: and dead reckoning is estimating the position of your boat
Speaker 1: without reference to any new markers around you, but rather
Speaker 1: by knowing your past position and estimating how far you
Speaker 1: have traveled from there and in what direction. So this
Speaker 1: is crucial to keeping track of your journey. But this
Speaker 1: is a different thing because it's not giving you new
Speaker 1: information from your surroundings. It's rather a sort of keeping
Speaker 1: track of your position on a mental map by just
Speaker 1: using the information already in your possession. And one mental
Speaker 1: tool that seems to help with this process and Pacific
Speaker 1: navigation has been referred to as attack. Again, this is
Speaker 1: not a means of acquiring new information from the environment,
Speaker 1: but rather a visualization or a mental reference system for
Speaker 1: understanding one's place in relation to other things. Unfortunately, this
Speaker 1: is yet another concept that is kind of hard to
Speaker 1: explain without visual aids. But Rob, I've got a visual
Speaker 1: aid for you to look at here, and I will
Speaker 1: do my best to try to explain it. Basically, it
Speaker 1: hinges on having this mastery of relationships between stars, vantage points,
Speaker 1: and various geographical locations, specifically islands on in the nearby surroundings.
Speaker 1: So as a point of analogy, imagine that you want
Speaker 1: to travel between New York in Chicago by stars. One
Speaker 1: way that I can help understand where I am along
Speaker 1: my journey is if I have a third reference point
Speaker 1: in mind. So let's say Atlanta. So I know that
Speaker 1: I start in New York, and when I start in
Speaker 1: New York, I know from where I am, Atlanta is
Speaker 1: going to be under Star A from my point of view.
Speaker 1: So if I wanted to travel to Atlanta, I would
Speaker 1: take my beer, I would head towards Star A on
Speaker 1: the horizon. But by the time I reached Chicago, now,
Speaker 1: because I'm at a different vantage point, Atlanta is underneath
Speaker 1: Star C from my point of view, and there's a
Speaker 1: midpoint in between Chicago and New York where Atlanta, from
Speaker 1: my vantage point is underneath Star B. So the whole
Speaker 1: time I never see Atlanta. But this mental reference system
Speaker 1: allows me to break my journey into recognizable segments where
Speaker 1: I keep track of each time the third reference island
Speaker 1: or in my analogy, Atlanta has moved under a new
Speaker 1: star from my point of view. Does that make sense? Yeah,
Speaker 1: I think so. And this this visual reference helps a bed. Yeah,
Speaker 1: I'm sorry you folks at home can't see it, but uh,
Speaker 1: actually you know if you do, if you do just
Speaker 1: a Google search for etach reference points, I don't think
Speaker 1: you will find the exact um illustration that I'm looking at,
Speaker 1: but you'll see some that are similar to They give
Speaker 1: you an idea of what we're talking about. It's e
Speaker 1: T A K. Yeah, though it's complicated by the fact
Speaker 1: that this appears also to be the name of a
Speaker 1: like a car navigation system, uh software. So if you
Speaker 1: if you Google attack islands there you'll see the right illustrations. Yeah, yeah,
Speaker 1: that'll cut out some of the car stuff. But I
Speaker 1: think this system is is also really interesting because it
Speaker 1: I think it still is important to think of it
Speaker 1: as a useful tool for navigation, even though it provides
Speaker 1: no additional information to the navigator. Instead, what it is
Speaker 1: is it seems to be that it's useful as a
Speaker 1: system for mentally keeping track of the information you already have,
Speaker 1: for knowing how far you've come, where you are, and
Speaker 1: how far you have left to go. Uh, which is
Speaker 1: interesting because I mean, obviously that's an important part of
Speaker 1: of any travel, right, is sort of visualizing the whole
Speaker 1: of your journey in ways they're not immediately apparent to
Speaker 1: your senses. Yeah, and I guess as in modern travelers
Speaker 1: with modern instruments, being at sea or on land, Yeah,
Speaker 1: we're still engaging in some level of that. We still
Speaker 1: have some level of a mental map, but we have
Speaker 1: these other tools that make our mental map less important.
Speaker 1: Maybe sometimes the mental map is even incorrect. Like you know,
Speaker 1: if you're if you're relying heavily on a GPS device
Speaker 1: to drive you from one point to the other. I
Speaker 1: guess you could theoretically not know if you're really driving
Speaker 1: north or west or south or what have you, as
Speaker 1: long as the system got you there. But in this case,
Speaker 1: the mental map is everything. The Milton in the mental
Speaker 1: map has to be carefully cultivated using uh knowledge of
Speaker 1: all of these environmental cues, these different systems. Uh. It's
Speaker 1: it's really quite quite amazing. Uh it's uh yeah, it's
Speaker 1: it's it's something else. So when you're driving somewhere new
Speaker 1: that you've never been before with the aid of a GPS,
Speaker 1: you know, like a map, SAP on a phone or something.
Speaker 1: Can Can you just plug it in and go? Or
Speaker 1: do you, like me strongly prefer to look at the
Speaker 1: whole route first. Um, I tend to just go the
Speaker 1: same way I do recipes for meals. It's just I
Speaker 1: just trust that. I mean, I look and make sure
Speaker 1: I have what I need. In the same case, I'll
Speaker 1: look at my gas tank and make sure I have
Speaker 1: enough gas to get where I'm going. I'll see how
Speaker 1: much how long it says it's gonna take for me
Speaker 1: to get there. But then I'll just go I'll just
Speaker 1: start cooking, or I'll or I'll just start driving and
Speaker 1: trust that I will get there and I'll figure out
Speaker 1: on the way of there any snakes. This must be
Speaker 1: differences in personality type somehow, I guess I'm I'm more
Speaker 1: annoying about this or something. I really don't like having
Speaker 1: to navigate based on just a moment to moment directions
Speaker 1: on an app without seeing the entire route first. I
Speaker 1: like to look at the whole map, see what the
Speaker 1: steps are, see how far it is, see like see
Speaker 1: it visually represented. That really matters to me for some reason.
Speaker 1: I mean, I might glance at it if if I
Speaker 1: know there's going to be some weird exit, if it
Speaker 1: says that, oh, I'm getting off at this exit, and
Speaker 1: normally I don't do that. I'm kind of curious what
Speaker 1: route I'm taking then, But otherwise I just go, well,
Speaker 1: you know. The weird thing is, I think one reason
Speaker 1: I do that, it's not like it usually gives me
Speaker 1: important information that I actually need in addition to whatever
Speaker 1: the step by step instructions in real time are. Instead,
Speaker 1: I feel like it's something closer to the attack system,
Speaker 1: where I just want to be able to visualize in
Speaker 1: this app stract way the whole of the journey and
Speaker 1: sort of imagine where I am along the journey at
Speaker 1: various points. M yeah, but I feel like I'm going
Speaker 1: to do that anyway as I drive, Like there's kind
Speaker 1: of a perhaps a less accurate version of that that's
Speaker 1: going to be going on in my head. But it
Speaker 1: says it's as accurate as it needs to be. Yeah,
Speaker 1: Like if the GPS satellites were to suddenly get taken
Speaker 1: out by aliens or something, um, you know, I could
Speaker 1: I get backtrack or even if it's if I've driven
Speaker 1: this particular route before, I can probably remember the rest
Speaker 1: of the way. Um, But otherwise I'm good. Well, I
Speaker 1: wonder if we should call part two there and then
Speaker 1: come back in part three to talk about one of
Speaker 1: the next really interesting things, which is all of this
Speaker 1: has been mostly about navigation, direction finding and navigation, especially
Speaker 1: on the open sea, but a whole other part of
Speaker 1: this science of navigation is land finding. When you're getting
Speaker 1: close to an island, how do you know that and
Speaker 1: how do you find it? And so let's save that
Speaker 1: for part three. Yeah, part three, we will we will
Speaker 1: make landfall or try to make landfall appropriately. All right.
Speaker 1: In the meantime, if you would like to check out
Speaker 1: other episodes of Stuff to Blow Your Mind, you know
Speaker 1: where you can find them in the Stuff to Blow
Speaker 1: your Mind podcast feed. We have core episodes of Stuff
Speaker 1: to Blow Your Mind on Tuesdays and Thursdays. On Monday's
Speaker 1: we do a little listener mail. On Wednesdays we do
Speaker 1: short form episode we're calling it the Artifact, and then
Speaker 1: on Friday's we do Weird How Cinema. That's our time
Speaker 1: to set aside most of the science and the culture
Speaker 1: and just talk about a weird emotion picture and then
Speaker 1: we have reruns on the weekend. Huge thanks as always
Speaker 1: to our excellent audio producer Seth Nicholas Johnson. If you
Speaker 1: would look to get in touch with us with feedback
Speaker 1: on this episode or any other, to suggest a topic
Speaker 1: for the future, or just to say hello, you can
Speaker 1: email us at contact. That's Stuff to Blow your Mind
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