by C. Litka
04
I feel I should mention how we navigate the sky-seas of Pela in the Saraime. You can skip ahead to the next section if you're not interested in these little details of my trade.
The technologically advanced shipping lines, the ones with ties to the core islands, like the S&D Line, all employ radar. The Telrai Peaks, sailing within the Donta Islands, relied mostly on radar fixes to known islands to navigate. Though my place was in the engine room, I was, after a time, allowed to observe the navigation and ship handling in my free time. I made a point to do so. You never know.
However, once you leave the (more or less) fixed points of the islands behind and get out of radar range, navigation becomes a great deal less exact, though Saraimian navigators have tools that make crossing the wide, island-less skies fairly routine.
The first tool is a gyroscope course plotter. The spinning gyroscope, once set on a course, alerts the helmsman to any deviation from the set course, using an alarm and array of lights. Keep the center light lit, and you're on course. In addition, most machines record the course on punched paper tape that notes the elapsed time and any changes in course so that the ship can use this record in reverse to return to its original starting position. In theory. In practice one also had to take into account the movement of the air through which you are sailing. There is a great deal of unpredictable churn in the vast atmosphere of the Pela and without a fixed reference point, this drift is impossible to accurately measure during the voyage. The longer the voyage, the greater the margin of error these air currents introduce. However, the chains of islands within the Saraime are large enough, and the sky-seas between them narrow enough, to make it nearly impossible for a ship equipped with a gyroscope course plotter to miss the island group, unless caught in an exceptionally powerful serrata. A ship like the Telrai Peaks, and even the Lora Lakes, if prepared and competently handled, could ride out most serratas without being driven too far off course. The serrata that the old Bird of Passage experienced was not only a very powerful one, full of debris from the islands, but coming out of a cloud bank, it caught the Bird of Passage broadside and unprepared, with ultimately fatal results. The Lora Lakes, bow on to the serrata would likely have carried along for a while in the initial squall and then fight it to a standstill, once the leading blast had passed, and then continue on its original course. Back to the gyroscope. The vector-courses from island port to island port are known. The initial courses are carefully set using a series of radio beacons and guide towers in every major harbor and once the ship is properly aligned, the gyroscope is set and the ship sails along this predetermined vector, with only the effects of the air currents over the course of the voyage to deflect it from arriving precisely off its destination. For most routine voyages within the Saraime, the gyroscope will bring you within ten kilometers of your destination.
Since our voyage was both a long and an uncharted one, the captain ordered the engines stopped twice each round and then recorded the direction and strength of the air currents we were sailing through as the ship drifted to a stop. These readings were logged and used to estimate the ship's drift so that they could be added to the gyroscope record if need be. Since we were steering by sailor's sight rather than by any charts, this was just a precaution in case something happened to DeArjen. The Captain, prudently, wanted to be able to find her way home without him.
There is a second tool, usually but not always, used in tandem with the gyroscope. It is a photo-electric sensor, a so called "bug eye." It is a concave disk with a number of individual photo-electric cells set on it. The larger the disk and the more photo-electric cells it has, the more accurate it is. Each cell is baffled so that it receives light from only a small section of the sky. Though there are uncounted islands that lay between any observer and the obscured orb of the Tenth Star, the spot where it lies is still slightly brighter than any other spot in the sky. You can't tell the precise spot by eye, but the photo-electric cells are sensitive enough to identify this spot to a fair degree. The 'bright spot", as it's known, is the one fixed point in the Pela, though without any up and down, east, west, north or south, by itself it tells you only if you're going towards the center or away from it, and the brightness of the sky itself will tell you that. However, if you have a second known point, you can set a course relative to the bright spot, and then use the bug eye to align the ship or boat on this course and then navigate by steering the vessel so that the bug eye remains centered on the bright spot. Again, depending on the air currents, this method may not take you exactly where you are going but, depending on the distance, within a reasonable margin of error. Pela navigators are comfortable sailing the wide-sky-seas with these uncertainties.
Smaller and more primitive boats and ships which don't usually venture far from known islands also use charts like the Bird of Passage had that give bearing and time/distance measurements and visual clues to the larger islands. Many also use a simple version of the bug eye - a concave sieve, with an opaque backing, that filters out all but the brightest spots produced by the sieve. And, I gather, many a ship captain has something like the sailor's sight, even if it merely arises out of long familiarity with the wide-skies he or she sails.
I realize that the fine points of navigating the Pela may have a very limited audience, but I felt it necessary to explain why sensible people would undertake a long, open-ended voyage across a vast island-less sky-sea on the "talent" of a perhaps crazy sailor, and expect to get back. I'm not saying it wasn't foolish. I had strong misgivings about the whole program, but it was a practical proposition on the face of it. It's the wisdom of it that I questioned.