Noise

III Score

“’Ao, take the tiller—no, let it swing and drop the sails. Mike, we need your muscle. Get as much cargo as you can out of the port hull and into the other. Never mind about nice stowing, we can see to that later. Keo, any food, air, and water equipment not in the cabin to the starboard hull, except the kumu’rau. At least it’s not out; make certain it’s secure. I’ll cut rigging and unclip the deck as fast as I can. If I’m not done when you’ve finished the life-stuff, then help me. Tere!”

Hoani quickly saw another reason why they had been so quick loading up with iron in spite of its density, and how Wanaka had kept busy between emptying buckets. Each purse of metal dust was now clipped to a balloonlike float whose volume sharply limited the space for actual cargo. None of these items was heavy and he thought he could fill the other hull quickly, but when he tried to carry several purses at once Wanaka cautioned him about the fragility of the floats.

Hence, a lot of cargo was still untouched when the gunwale of the port hull dipped below the surface. Mike thought of closing the hatches to delay flooding, but before he could make the suggestion the captain must have guessed his thought. She shook her head negatively.

There were readable expressions on the four faces as their owners watched the port hull of the Malolo be pushed slightly below the surface by the still attached deck, but it was only annoyance. Showing fear or anger in public, even if the public were mate or sibling, was rude on Kainui, and so far neither of the informed adults felt any real fear. Mike wasn’t sure whether he should, but decided to be guided by them. The youngest member of the group might have been slightly afraid or even terrified, but was not going to let anyone else know it.

The fact that neither ship nor city could be seen within the haze-limited vision in any direction surprised no one, and of course Mike, the only one who had ever seen land, knew better than to expect that anywhere on this world.

The swell was high, but its wavelength was great, far longer than the catamaran’s hulls; almost too long, just now, to let anyone see one crest from the next through the haze. In the water world’s gravity, waves moved so slowly that the five-meter rise and fall of the drifting wreck was not noticeable—would, indeed, have been fairly hard to measure.

“Keo. Take over from Mike. Free as much cargo as you can. I’ll take the deck clips. ’Ao, salvage any stowed line from the lockers first, then get the sails. Don’t waste time with knots. Cut the lines, but be careful of veins and valves. We don’t know when or how fast or even whether that hull will go down. Mike, stay with me, and provide any muscle help I seem to need. If I’m under water and can’t talk, use your eyes and head.”

There was no argument. Keokolo was seven Kainui years older than Wanaka, nearly twenty centimeters taller, fifteen kilograms more massive, and her husband; but her seamanship rating predated his by over two years. This would automatically put her in charge in any outcity emergency even if she had not been the registered owner and commander of the Malolo. Also, shifting cargo that was already under water, even cargo packed to float, would call for muscle; she had divided the duties sensibly. Keo nodded, donned helmet, and slid into the sea.

’Ao did the same, swimming to one of the forward lockers of the awash hull and cautiously releasing its latch. Wanaka watched the child for a few seconds, decided she would need no help and was unlikely to panic, and turned back to her own task of freeing the quick-disconnects that attached the deck to the starboard hull. The latter was listing dangerously as its twin dragged it downward; the crew had already been forced from deck to coaming. If its gunwale dipped under, the commander’s hope of salvaging any significant part of her cargo would sink with it.

She was not greatly worried about having to drift for a year or two, but she valued both the metal and her self-respect. Also, if they were rescued before chancing in sight of a city, the rescuers would be entitled to much of the cargo.

Two minutes’ work freed the starboard hull from its dangerous burden. The deck slid off, or the hull went out from under it—none of the workers bothered to decide which; the important point was that the long, slender structure righted itself before going gunwale under, and crew and cargo still had something presumably navigable to ride. Mike followed Wanaka below the surface.

Keo was still engaged with the cargo lashings of the sinking hull; package after bubble-floated package of iron dust was being freed and rising slowly toward the surface. ’Ao had apparently finished the coils of rope in the lockers with commendable speed and was now slashing rigging lines from the mast and yard, obeying the order not to waste time with knots. Also commendably, she was looking around continually, and saw the captain’s approach.

“How much ready cord did you get?” Wanaka gestured as she swam toward the child.

“There were ten eighty-meter coils of tow line, and four two-hundred-meter drums of rigging cord,” she replied promptly.

“Did you stow them?”

“No. They’re floating. I thought I’d better get to the sails in case they got pulled too deep when the hull sank.”

“Good. The metal is most important now, though. I’ll help Keo with that, and you join us when you get the sails aboard. We’ll stay on the starboard hull unless and until the port one actually does sink. Then we’ll string and tow everything we’ve saved—the starboard hull is pretty full. We’ll hope the weather stays calm long enough to get things roped together and at least start the growing. Come on.”

The weather obliged, though the suns were quite low when the job ended and work had been slow during the eclipse. ’Ao finished her last knot, dived, and swam back to the nearly awash hull to examine the ulcers near its bow.

The captain tapped her as firmly on the shoulder as the water allowed, and signaled sharply. “Keep away from that! You can see what it did to my ship! Do you want the same thing to happen to your suit?”

“But my suit isn’t made of the same stuff. Whatever this is shouldn’t infect it.”

Wanaka’s gesture was not a word symbol. She pulled the child toward her, spun the small body to face away from her, and did something to the twenty-centimeter disk between ’Ao’s shoulders. Mike noticed that no tools were needed this time. ’Ao tried vainly to pull away, but the captain maintained her hold and finished what she was doing. A moment later the adults were stroking slowly back toward the intact hull while the smaller figure swam furiously ahead of them.

By the time the older ones broke the surface, their charge was aboard, sitting hunched up in the stern looking away from them.

“’Ao. We still have to string bags. We can’t keep all this stuff aboard.” Keo spoke, judging that she was more likely to listen to him at the moment; he didn’t know the details of the under water exchange, but could guess closely enough.

“String them yourself. You don’t want me to help. Wanaka took points off me just for arguing, and I have a right to argue if you don’t explain why you—”

“It wasn’t for arguing—” the captain interrupted. “It was for ignoring a warning. You stayed right beside that infected spot while you argued. I know your suit is made of something different from the hull—of course it is. The two hulls are made of different materials and have different coatings for the same reason.”

“I know. I was going to remind you.”

“Did you know that the hull we’ve just lost had four protective layers, all of different composition, and that all have been penetrated? Do you know anything at all about oxygen gangrene?”

’Ao turned sharply. Her tear-stained face could be seen around her mask, along with its expression of surprise. “No! I—well—I—”

Keo, too tactful or too kindhearted to force an apology, answered her. “I’m sorry no one told you that, but you did know water was getting in. Don’t worry; you can earn the points back. We’ll be a long, long time getting home. Half a year, I wouldn’t wonder, maybe a lot longer. There’ll be plenty of time for you to do it.”

All three looked up at the setting suns. Pahi, the brighter, was above and somewhat to the left of its slightly cooler and fainter twin. There was no overlap just now, but all three knew that Pale was slightly closer to them at the moment. No one really cared yet; such details as eclipse phenomena were important only during the final and most precise stages of a navigation problem. All but the least sea-oriented residents of Kainui, however, tended to keep aware of the general celestial status.

’Ao, without another word, went to the nearest hatch, took a coil of tow line, and began tying together the float-equipped sacks of iron dust and letting them go overboard. Keo finished climbing out of the water and stood as tall as he could, looking around to see whether any of the salvaged material had been missed and not yet moored. Some had, so he, too, plunged back in. Taking a coil of the light line the child had salvaged, he made his way to the farthest of the bags, and began methodically making crochet loops in his cord and tightening them around the prongs with which each float was provided.

Several times he returned to what was left of the Malolo to recheck his view from as high as possible, while ’Ao sat where she was and turned cargo into towage. The starboard hull was already too full, and none of the most recently salvaged material could be kept on board. Any ordinary rain-or-hail storm could drop the ocean’s surface density enough to let the craft settle dangerously with its present burden; at this latitude—Malolo had shifted to an almost southward course after leaving the copper-fish—even the poleward-eastward relatively fresh surface current from the equatorial rain belt had picked up a fair amount of salt and could be diluted significantly by precipitation.

Rising wind interfered with the last part of the operation, but they lost no bags, to the captain’s satisfaction. Everything they could find and catch had been secured, and the second stage of their problem could be faced.

Navigation on Kainui was complicated by the world’s having no fixed reference points other than the rotation poles, which were too abstract to be found without rather complex celestial observation and much too far from where Malolo was now to be useful. Muamoku, the floating city that was their home port and nominal eventual goal, did not remain in one spot, though like the other cities it maintained latitude fairly well. No one really cared; as far as anyone knew, every part of the planet was like every other part except for current patterns, surface salinity, and coverage of floe ice. These varied with latitude, with minor statistical differences in frequency and intensity of storms, and with the percentage of ocean locally filmed over by fresh water or ice. There were no natural icebergs, since there were no islands or continents to build successive snowfalls up into glaciers. Even the surface water was extremely salty in many places and hence hard to freeze, but Kainui and its slightly smaller twin Kaihapa were far enough from the suns to freeze plenty of floe ice in the high latitudes in the winter hemisphere.

There had been attempts in the distant past to harvest ice from the southern cap and supply water that didn’t need desalting, but unfamiliar conditions at the polar region seemed to have caused the disappearance of too many of the ships involved.

“All right, ’Ao, what do we do with the sails now that the mast can’t be used?” Wanaka felt that she had been a little severe with her punishment and hoped that the youngster could earn the lost points back quickly. She had no intention, of course, of broadcasting her doubts by canceling or reducing the penalty.

“We use them as sea anchors under water. The wind won’t help anymore. Muamoku tries to stay at the south edge of the southern trades, and I don’t really know even that much about any other cities. We’ll have to rig a sea anchor and sink it far enough for deep flow to keep the surface current from taking us too far south. Then we can start—”

“How do we know the right latitude?”

The visible part of the child’s face showed she had spotted the trap. “We don’t need to. It doesn’t matter as long as we don’t get too near the ice. The suns will warn us of that, and I think we can check stars, too, but I expect you’ll show me all that.”

If either Wanaka or Keo was amused by the skillful return of the ball, neither let it show. The man nodded.

“You have the right idea, little one. You can help us rig the sea anchor if you’re not too tired—”

“Of course I’m not!”

“Not tonight—” the captain interrupted. “Almost time for food, drink, air check, and sleep. In the morning we’ll bend lines to the sails and get them back in the water, the sooner the better; the wind isn’t taking us the way we want to go, and certainly the surface current isn’t either. We’re drifting—can you tell me which way?—and we’re already way south of the city.”

“South and some east, I suppose. That’s what surface currents should be doing around here.”

“How were we sailing before the hull began to sink?”

’Ao blushed visibly around her mask. The catamaran had not been traveling downwind, of course, but at an angle to it that would provide maximum speed. The more ocean that could be covered by daylight, the better the chance of spotting cargo. The child thought for a moment before she could remember which tack they had been on, and risked a guess. “Well, pretty near south.” Wanaka smiled, slightly relieved.

“Not too bad. About one-sixty. All right, back to work. We can’t accomplish very much more tonight, but should do what we can of the obvious procedures before dark.”

’Ao splashed her way to the partly submerged cabin. She was still unhappy from the recent chastisement, but had learned not to argue a point when she knew she would, whether right or wrong, lose the argument. She would eat before being ordered to.

The emergency nourishment provided by noise suits was not particularly tasty, and she had been solemnly warned that people in suits outcity sometimes went dangerously long without eating or drinking when their minds were taken up with other matters. A twenty-year-old had that fact firmly impressed on him or her before ever going “outdoors”—leaving the limits of a city even in a small boat. ’Ao had no wish to lose more points on the same day, and showing initiative might even have the opposite effect.

She finished quickly, however, emerged again from the still floating cabin—Mike had wondered why the air lock sill was half a meter above deck level—swam to the formerly starboard hull, and moved cautiously along it to where the salvaged sheets of fabric had been rather hastily stowed.

“D’you know which was the big one?” Keo, who had followed her, asked. The child nodded and began working the appropriate sail out of the pile. The man took her at her word and began threading a length of cord through each grommet as it came into view.

The captain gestured to Mike to accompany her and swam to the cabin.

The passenger had been wondering why the sail could no longer be used in the normal fashion. Now he found out. The cabin had slid off the now detached deck; apparently some more quick-disconnects had been operated. The mast, still stayed, had fallen over, tilting the deck to a vertical plane as it did so. Wanaka ducked under the cabin, gesturing Mike to follow, pointed out to him a D-ring at the under edge of its floor, and made a pulling gesture. Hoani started to comply, but she stopped him, making a complex but meaningless gesture with one hand and, much more informatively, grasping his wrist with the other. Then she pointed to the opposite side of the cabin and swam toward it, motioning him to follow.

There was a similar ring on this side, which she took in her own right hand. Then she pointed back to the other side, extended fingers successively in a one-two-three gesture, and simulated pulling the ring herself.

Mike nodded comprehension, swam back to the first ring, and took hold of it. Wanaka made the gesture of approval he had seen earlier, which had clearly originated on Earth but not in any Polynesian culture, and repeated the one-two-three signal, pulling her ring at “three.” Mike did the same. He was not too surprised to see two rubbery sacks rather longer than the cabin floor begin to swell very slowly. The importance of backup had apparently taken a firm hold on Kainui. One could see why.

He had already learned that sailing craft were extremely expensive here, simple as their basic growth ought to be; now he began to see why that was, too.

The expansion of the floats was so slow that he wondered why it had been important to start both of them at once, but he never remembered later to ask. The captain swam to what Mike still thought of as the after end of the cabin, pointed out two more rings much closer to its center line, and they repeated the coordinated pull. Two more floats began to swell.

It took fifteen or twenty minutes for the filling gas bags to lift the cabin clear of the sea. Mike assumed that the gas was not coming from pressure tanks but was being generated by some form of pseudolife. There would be no way to ask until they got out of the water, however. There seemed no immediate prospect of that; all three of the crew, aided by the unskilled passenger when he could be shown what to do, were engaged in what were presumably life-or-death tasks as Malolo gradually was transformed from a sailing catamaran into something of dubious drive source, with its former mast divided in two—there were telescoping sockets along it—to form cross members connecting the remaining hull with the cabin, making the latter a highly inefficient-looking outrigger. There were connectors in the right places for this job, too.

Wanaka did not abandon the separated deck, to her passenger’s curiosity. This had tipped back to horizontal and floated awash when the mast stays had been cut. It seemed incapable of carrying anything useful; even little ’Ao’s weight pushed a side or corner under the surface unless she balanced herself very carefully at its center. She was amusing herself trying this when the captain ordered her rather sharply to get back to work.

The three adults were now all out of the sea on the remaining hull; it was not necessary to use hand language. Mike could interpret tone as well as words. The child complied instantly without even looking indignant. Her doll, once more perched on her shoulder, made no comment either.

Mike, fully appreciating his own ignorance, decided not to ask about the deck just then. Also, he kept quiet on another point: after sunset there had until now been a light at the top of the mast whose purpose seemed obvious, but there was no suggestion of replacing it on, say, the roof of the cabin, though even the fainter sun was now almost below the horizon. He wondered what the chances might be of their being run down by another vessel in the dark.

His reluctance to look ignorant overweighed his slight worry that the others might actually have overlooked that matter. Once the still floating hull had been attached to the sections of mast and the latter in turn to the floating cabin, he entered with the others and settled down to the usual evening activities.

“Usual” was not quite the right word; it was the first time all four of them had been inside at once for more than a few seconds since leaving Muamoku. Also, there was much more than usual to do with the life-support equipment. Mike couldn’t help much with this, but watched and listened to explanations, mostly from ’Ao, as the adult crew members toiled. The least pleasant of the explanations made it clear that they would possibly be eating suit-type synthetics until further notice once the parting gifts from the other ship had been used up. The pseudoplants that produced the more palatable substances might or might not survive their recent immersion; they had been on the deck, and Keo had not gotten them out of the water immediately. The realization that the suit synthetics had been most carefully designed to provide all possible human nourishment needs for an indefinite period did not offset the evident fact that taste had not been considered in the listing of those needs.

Or possibly, Hoani told himself, the notions of what tasted good had also diverged in the last few generations from Earth-human-normal. He promptly corrected that term in his mind to Hoani-personal-normal. There is a broad spectrum of “normal” human tastes.

Eventually the most urgent tasks seemed to be done, and everyone ate once more, quite slowly this time. Then the child was firmly gestured toward her hammock, and Keo without orders tumbled onto a bunk. Mike decided it would be tactless to claim the other, even though Wanaka showed no signs of being ready for it. She settled down to paperwork—Malolo’s log, mainly. Mike began to put his own copious mental notes of the day into permanent form, up to the minute.

He finished before Wanaka did, but eventually she stopped writing, too, and looked up from her desk.

“A nonstandard day,” she remarked with no sign either of annoyance or humor. “You must have a few questions.”

“Some,” he admitted, “but I’m figuring out quite a bit for myself. If the kid isn’t going to spend any more time at a masthead, maybe you could have her start teaching me Finger.”

Wanaka nodded. “Good thought. I doubt that either Keo or I will be able to give you as much attention as we hoped.”

“That’s all right. She knows enough more than I do to be an appropriate teacher anyway. But I can’t help wondering whether she could tell me much about what turns the oxygen I heard Keo mention into a danger. I could only infer from the spoken words after the episode under the hull that she didn’t know as much as she should about it, so maybe you should tell me.”

The captain smiled wryly. “She can tell you as much as either of us could. She was dangerously careless, and I had to downgrade her for it. But I may as well give you the picture.

“It’s nasty stuff. You probably know that not everyone on Kainui is completely agreed about everything.”

“I’m ready to take that for granted. You’re human.”

“Some people want to get a lot of oxygen into the air and at least get rid of the carbon monoxide. This, to be managed in less than a good many generations, would require pseudolife able to reproduce itself indefinitely—the sort of thing we told you back at the iron-fish that most of us consider unacceptably dangerous. Others remember too clearly the unforeseen side effects of that sort of seeding on a lot of worlds, including the Old one. The result, since there’s never been any way to stop people from using knowledge once it’s been acquired, is that some folks, and some whole cities, have gone ahead designing and releasing pseudos able to break down water, and others to take the oxygen and react it with CO before the freed hydrogen made a nuisance of itself, interfering with the redox we use in the city and on board here. Usually these things have been grown as symbionts. Unfortunately, while officially designed systems have so far behaved fairly well, some of those designed by hackers—individuals with less interest in social approval than in displaying their own skill—have gotten loose with some pretty sad side effects. No doubt their planners meant well, but having to keep a project more or less under water divides attention, and not knowing what other people were doing in the field—well, you’ve probably heard the story of a couple of nations having political disagreements back on the Old World. One of them sabotaged the guidance system of a missile being tested by its enemies, and targeted its makers’ capital, not knowing that another department of its own government had already sabotaged the warhead. Not an unusual event in complex societies, or even in our quite simple ones.”

“So there are oxygen-producers loose on the planet, not all of them putting their product to its best use.”

“Exactly. And several types will leave the oxygen free to attack many other sustances than carbon monoxide. For the last couple of centuries cities as well as ships have had to keep a constant watch for such stuff. Nowadays we also have to watch out for people who dream up organisms which will act as predators for such oxygen-producers. These also, of course, have to be unlimited breeders. I’ve heard an old aphorism about the perils of riding a tiger, and I can see its implications even if I can only guess what a tiger is.

“Anyway, we’ve picked up a dangerous oxygen-maker. It’s lucky it takes so much energy to break up water, and the things that don’t dispose of the oxygen properly usually don’t get much of it back. I do wish I could promise we could get you back to Muamoku. But we told you about that before we started.”

“You did. No blame. I may have been safer crossing nineteen hundred parsecs between the stars, but I doubt it.”

“Anything else you’re curious about?”

“Lots, but you couldn’t cover it in one night. I gathered the kid did something out of line? Part of what went on was in Finger, and most of the rest out of my hearing in the thunder. Don’t give me details that you consider none of my business, but I wouldn’t want to make any verbal slips that might either bother the kid or undercut discipline.”

Wanaka glanced at the hammock and gave a terse account of what had happened. She skipped her own doubts about the punishment, since she was not completely certain that ’Ao was asleep. More to the point, she was quite certain that the doll wasn’t.

Mike nodded as she finished. “All right. Remaining worry: just how sure can we be that that gangrene was confined to the hull we’ve shed?”

“I rather expected you to ask that. If you were wearing a rank badge I’d award you a couple of points. We aren’t sure at all. My guess is that when we hit that whatever-it-was a while back—you remember—we picked up the infection. We’ll never know just what the object was, but I’d guess either an egg designed to make oxygen seeds or more likely a bit of coral which had been around long enough to pick up practically anything. Viruses grow best on a solid surface, almost always. We pushed off the old hull, and I hope it sinks; but we’ll have to check the one we still have carefully and frequently from now on.”

“Something just occurred to me. If oxygen-producing pseudos aren’t capable of direct reproduction, couldn’t Malolo’s breathing equipment get infected?”

“It could. We carry several carefully packeted seeds for replacing that gear; and another possible source of our present infection would be a minor mutation of such a seed lost from another ship.”

“Or maybe our own? Infecting from inside the hull?”

Wanaka raised an eyebrow, but showed no indignation. “That’s conceivable, and we’ll check. The seeds were, and I think still are, in the cabin, though. Thanks for the idea—I guess.”

“And if the other hull goes, too? I was very impressed by your built-in trouble preparations, but there must be a limit to what they can handle.”

“There is.” The captain offered no more details, and Hoani decided not to press the point. He himself felt that knowing the worst was no more likely to bother him than not knowing anything, but Wanaka was the captain and he, by now, was quite clear about most of the implications of that fact. That was one reason why he had hesitated earlier before asking about ’Ao’s offense.

Wanaka went on, “I’m going to sleep. Since we aren’t under way, there’s no risk of hitting anything, and if anything hits us there’s not much to be done about it at night. Sorry, but you’ll have to sleep on the deck.”

“The one outside? Is that why you kept it?”

“No. The deck—floor—in here. Your breathing gear wouldn’t last outside. I’m sorry if you don’t sleep well, but we could be sorrier if I don’t. Au ahiahi.”

Mike did not, in fact, sleep very well. He was pretty sure that the chance of being struck by anything must be considered negligible by the professionals, since they had both retired without setting up a watch, but he frequently found himself awake and listening.

There was as usual plenty to hear, much of it muffled by the cabin walls, but none of it was informative. He could only guess how much of the night he spent awake, but did not feel very capable when the other adults sat up almost simultaneously. It was dawn, though neither sun was actually up. Kaihapa had not shifted visibly, but that was no surprise; it would have implied hundreds of miles of longitudinal drift in a few hours, which would in turn have called for a most impressive sequence of storms.

The captain left the chamber briefly, and returned with a report that somewhat eased Mike’s indefinite worries.

“The old hull’s either sunk or drifted away. Keo, check what we have left for infection, then come back and eat, and we’ll set up the deep-sail and seed. Mike, how good are you at knots?”

“Hardly up to your standards, I’m afraid. But I have sailed on Earth.”

“I know. All right. When Keo gets back we’ll wake up ’Ao if she’s still asleep, and she can join Keo and me. I’m afraid you have to stand—and I do mean stand—watch on the other hull, Mike.”

Hoani realized that the “I’m afraid” part of the sentence was pure courtesy to a guest; he’d actually been given an order. He acknowledged it appropriately.

Keo was fully twenty minutes at his hull check, but finally reappeared to say that everything seemed to be clear. Mike, the captain, and the now awake ’Ao all noticed the choice of words, but no one remarked on them. They ate, checked their own and each other’s breathing equipment, and went outside. Hoani would have liked to watch what the others were doing, but controlled his curiosity, swam to the hull and climbed onto it, and promptly had his attention taken from the others.

The sea legs he had acquired earlier were now out-of-date. The hull was less than two meters wide, and responded very differently to swells and microtsunamis than the catamaran configuration did. Also, there was much less to hold on to when he stood up. By the time he was actually able to get his attention away from his own feet, the others were all under water. He hoped he could find one of them if he had anything to report.

It was the most boring morning he had spent since leaving Muamoku. It was also the most tiring; standing in the one-third gravity was not burdensome even in noise armor, but the constant change of stance needed as the hull pitched, yawed, and jumped called for equally constant muscle work. He was quite proud of himself when the others surfaced and joined him; he had not fallen overboard even once.

He yielded to temptation and watched the final operation of the others rather than their surroundings. The deck—the original one—had been moored to the stern of the hull the night before; now an additional line was strung between it and the cabin. Keo took the hull end of what had now to be considered a control line, while Wanaka worked her way onto one of the cabin’s floats and juggled with a second. Very gradually, Mike saw, a short and feeble wake appeared at the bow ends of hull, floats, and deck. Something was pulling the whole assembly, very slowly, aft, or at least keeping it from moving with the southeast-bound surface current.

A few minutes of watching and thinking provided him with a reasonable guess, and encouraged him to ask a question of Keo.

“How deep is the sea anchor, and how can you keep it there?”

The native answered without taking very much of his attention from the tow line.

“Between seventy and eighty meters. We’ve weighted it with some of the iron, and floated one corner to keep it more or less vertical, and attached the smaller sail to help handle the high corner. It was tricky arranging, and if we lose too much of the speed difference between the deep and surface currents it’s unstable. If it goes too far down the whole vertical line of floats will collapse under the pressure and let the stuff sink, and we’ll have to set it up all over again. As long as we’re being pulled hard enough one way by the surface current and the other by the deeper one, the difference should tend to keep the whole thing up.”

“Why the current difference? Though I think I can guess.”

“Surface current is diluted water from the equatorial rain belt. It gradually picks up salt as it flows. The deeper one is saltier stuff returning toward the equator. That’s a gross over-simplification, by the way.”

“I thought it might be. How long will this stage take us?”

“To grow the new hull? Half a year, give or take quite a bit. Depends on temperature and a little bit on ion content of the water. To get to Muamoku afterward? Probably less, unless the captain decides to hunt up more cargo first.”

Mike found himself out of questions. Both of Keo’s answers needed digesting.