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Tori Angeli ([personal profile] tori_angeli) wrote2012-02-08 06:04 pm
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Sailing Basics #4: Directions and Navigating Places

It’s lucky for you her captain was so poor a navigator, hm?  Else we might never have found you.
-Cpt. Pellew

Now.  Most people by now know fore, aft, starboard, and port.  On board the Britannia, the term “port” is less likely to be used as a reference to the left side of the ship.  The term used at the time was larboard, and when you say it out loud, you’ll understand why they changed it, being so easily confused with “starboard” when shouted during a squall.  But that’s what we have.  Starboard and larboard it is.

A quarter can refer to a couple things.  In the case of direction, it refers to literally a quarter of the ship aft of the beam (the widest part of the ship).  The “starboard quarter” is the right side of the ship abaft (behind) the beam.  The larboard quarter is the left side blah blah blah.  On the other hand if someone talks about a quarter, they can be talking about a division of men.  Britannia doesn’t really have a large enough crew for everyone to be divided into divisions, though, so.

What’s the equivalent for the bow?  The bow.  If you refer to the “larboard bow,” you’re talking about the front-left quarter of the ship.  But what if the enemy ship is right in the middle, starboard side?  Then they’re on the starboard beam.

What if you want to be more precise?  Use compass points.  The compass is divided into thirty-two points (the ship has a compass in the binnacle, a post built for having an embedded compass, by the helm).  If you want to be specific, you can sound amazingly smart by telling someone how many points abaft the starboard beam something is.

Here is how such a conversation could go.

Hiccup: Sail ho!
Hornblower: Where away?
Hiccup: One…no, two points off the starboard bow!
Hornblower: (noting that the sail is to leeward) Square away, if you please, Mr. Bush, and set course to intercept.
Helmsman: Starboard two points, sir.

So we know direction in relation to the vessel itself.  How about that amazingly daunting topic of (orchestral sting) NAUTICAL NAVIGATION?

Navigation by sea is, from what I understand (and I understand very little), a completely different beast from navigation by land.  By land, there are landmarks, roads, terrains, etc.  By sea, there is nothing besides natural and imaginary divisions of the Earth.  How do you know where you are when all you see in any direction is flat water?  This is where a sailing master, the chief navigator of a ship, comes in (Nami of One Piece could be considered a sailing master).  Now, any green midshipman is taught how to plot a ship’s position on the earth.  Hornblower even as a lieutenant made sure to plot the ship’s latitude and longitude every morning, but the sailing master, or just the master, makes nautical navigation their specialty.  Maneuvering is not a part of this, especially not in battle, although a sailing master has the know-how to perform maneuvers requested by the captain.

Norie’s Epitome of Navigation, published in 1805, was the definitive book on navigation at the time.  It defines navigation so:

“Navigation is that Art which instructs the mariner in what manner to conduct a ship through the wide and trackless ocean from one part to another, with the greatest safety, and in the shortest time possible.”

A master and his or her mates are going to be doing this all the time.  Making sure they know exactly where on the globe the ship is.  Figuring out how to get where they’re going, compensating for leeward motion that is inevitable unless one is completely squared away with the wind at their back.  The master also figures out when sunrise and sunset will be every morning.  Now, this is all stuff I am still learning myself, but this is the gist of what I have so far.

It’s math.  Lots and lots and lots of math.  So much math, in fact, that I just will not get into the details.  Suffice it to say that we are spoiled in this modern age by calculators, because I have read about how to figure sines, secants, tangents, etc. without one and it is a pain unless you are using logarithms, in which case it is less of a pain.  But that’s what it is.  It’s all about circles, triangles, arcs, and the distance between two points.

To plot one’s position upon the Earth requires the proper tool and a lot of math.  A sextant is especially famous for measuring the angle of the sun with the horizon.  It’s these angles and plenty of math that determine one’s latitude and longitude.  Anyone with a sun and a horizon can plot their position.  You can even hand-make a sextant.  Because.  Yeah.  In our day, sextants were all hand-made.

Now, I’ve spoken with Masa (who giggled at the word “sextant”), and it is possible to plot Luceti’s latitude and longitude if you’re using the assumption that this planet is like…whichever one you come from, with the same curvature to the planet and not, for example, a JRPG doughnut shape, and if you are assuming the existence of Greenwich, UK or some other “first meridian” for longitude.  Plotting the position of locations outside the enclosure is going to be handwaved as not quite working.  Celestial objects like stars are not at all the same from location to location outside the enclosure.

The speed of a vessel is measured in knots.  In the Age of Sail, this was measured by essentially chucking a weighted rope into the water and looking at how many measured lengths (marked by, you guessed it, knots) they went through in 30 seconds.  It’s roughly equivalent to a nautical mile per hour (about 1.8 kph or 1.5 mph).  Tall ships are not planes or cars.  They do not travel at super-speeds even before the wind.  The average speed of a vessel really depends on the vessel, but there seems to be something of a bell curve depending on the size of the vessel.  Tiny boats are slow and giant first-rate ships of the line are slow (“slow” might be 3-5 knots) whereas the Joanna Joyce might get up to about 8-10 knots with a fair wind.  No matter what, though, it always depends on the wind.  Sometimes, size is an advantage in speed.  Larger vessels carry more sail and catch more wind, and are less affected by weather and waves.  Still, the speed of a vessel does not depend solely on the vessel itself.  For example, with the wind at their backs, Joanna Joyce would undoubtedly beat Britannia in a race.  Beating to windward, however, Britannia has the advantage because size is actually a good thing when beating to windward, as discussed in an earlier entry.  It also depends on if your sails are spilling wind, whether deliberately or through poor handling.  Even with everything perfect, you can never sail faster than the wind.

How long does it take to sail from the shore to the farthest point of the Barrier?  Depends on the vessel and the wind, but probably no more than a day.  With good wind and fair conditions, about half that.  What about the perimeter of the Barrier?  I haven’t done the math yet, but I’d guesstimate it’d be two or three times the distance from the shore to the furthest point of the Barrier, so maybe 36-48 hours.  It’s oblong and I always sucked at parabolas in pre-cal, so I am not doing this.  If anyone catches my math being off, please tell me, because I would love to correct this.

This is all very complicated, isn’t it?  Well, there’s more.

A ship’s course is, to quote our friend Norie, “the angle which a ship’s track or path makes with the meridian, and is expressed either in points or degrees.  Thus, when a ship sails in a north-east direction, we say her course is 4 points, or 45 degrees.”

The distance is…self-explanatory.  It’s the number of miles between any two places on the course, or it is the “length that a ship has sailed on a direct course in a given time.”  That one was obvious.  Next!

The difference of latitude is “the distance which a ship has made north or south of the place sailed from and is reckoned on a meridian.”

The departure is “the east or west distance a ship has made from the meridian of the place she departed from, and is reckoned on a parallel of latitude.”

These are all things a navigator will keep tabs on at all times.  There is a different way to calculate, construct, and measure every one of these.  If you’re measuring, there’s a different tool for each.  Navigation is hard.

Eyes crossing yet?  It’s okay.  For RP, this is stuff you probably only need to know if you play an officer or navigator (midshipmen, you are being taught this stuff! But you are not likely to have to reference it in RP unless you are playing out a navigation lesson, which…why would you do that?).  Even then, it’s mostly terms to throw around so your character can sound like they know what they’re talking about.  If anyone, anyone, actually wants me to go into a Navigation: Part 2 sometime after I’ve read more about it and can get into detail without breaking my own brain, let me know.

Make note that this is stuff I get from reading a book that was definitive in 1805, and not even the entire book.  I am a student like you.  I cannot tell you if they use this stuff in the world of One Piece.  I cannot vouch for its usefulness in modern sailing, but if you’re that into the Age of Sail, Epitome of Navigation is a free ebook on Google and a fascinating read.

I think I have officially gone too far, though.

Next time: Important people and what they do on board a ship.

deathsdoctor: (Misc | Working)

One Piece - the Grand Line, a primer

[personal profile] deathsdoctor 2012-02-09 03:14 am (UTC)(link)
For information on the world of One Piece and sailing the Grand Line particularly, here is a wiki link directory:

General World knowledge

The Blues - normal oceans outside the Line.

The Red Line - this is the single continent that encircles the globe at the Prime Meridian. The Grand Line is at the equator.

On either side of the Grand Line - Calm Belts. You don't want to sail here.

Grand Line first half - Paradise

Grand Line second half - The New World.

And as a picture's worth a thousand words, here's a more visual representation of what a sailor would face entering this sea. Also an excellent comparison of how large wildlife can get vs. your average sized ship.

We also have Sky Islands which exist on Island clouds and surrounded by Sea Clouds which actually can be sailed on. Getting up here is hard and normally done by using a 'Knock Up Stream', though there are other methods not elaborated on in canon.

What you have to consider while sailing in these waters.

Wildlife - Sea Kings and other critters. In other words there is a lot in these waters that will try to kill you, eat you, and create navigation hazards for your ship.

Sea currents and whirlpools - They can get crazy.

Island climatic zones - Stable zones in the Grand Line where the weather and the sea currents are... more or less fixed in normal patterns per island. Each island has a unique magnetic field of varying strength, and one of four climatic zones (there are special cases and the New World Islands are more reality breaking.). Outside the stable zones, the influences from all the climatic zones and unique magnetic fields mix together to create unstable weather and seas, and make navigation difficult.

Places like the Florian triangle - One Piece's Bermuda Triangle, there are zones on the sea that ships go in and don't come out.

The weather - the Grand Line is deceptive and highly chaotic. On average a Grand Line storm will brew up within minutes, turning from a sunny day into a hell storm on par with what the worst of the Atlantic and Pacific have to offer. Bad storms are worse, with highly unpredictable cyclones appearing. The most dangerous things about these storms are the speed at which they hit and the lack of warning before they come. A successful crew will be highly aware of their surroundings, and where they are sailing. A rule of thumb for the Grand Line is the further down the Line you go, the worse the conditions can get.

Other phenomena - The Grand Line is a place where reality can sometimes seem fractured. There are islands where the sun doesn't set (Ennies Lobby), it rains lightning, the sea is on fire, and other things occur that defy the laws of physics.

Tools you need

Log Pose. Instead of a normal compass, you use one of these to cut through the magnetic interference and lock onto the next island. This takes a varying amount of time once you've arrived at an island to lock on the next. Good for going deeper into the sea... not so good for getting to a specific place.

Eternal Pose This always points to one island, and one island only, as it has its unique magnetic signature always fixed. These are useful for Marines and merchants who are trying to get back to a home base or specific ports of call.

Sea charts - These are gold, as they can detail all sorts of very important things like navigation hazards, climatic zones, and the location of a nest of critters you really want to avoid. As the Grand Line hasn't been fully explored, these maps are incomplete

Ship Coating - To access the second half of the Grand Line, most go through Fishman Island, located on the sea floor in a hole in the Red Line. This resin bubble allows a crew to survive and sail at any depth. This can be done at Fishman Island, Sabaody Archipelago on the first half of the Grand Line, and likely somewhere on the second half as well.

Everything you would use on the regular sea.