Day 10! 

Merrin has now survived on this planet for 1.5 months! Local months, that is. But it’s actually getting pretty close to a whole dath ilani month, counting by hours. 

It SNOWED last night. Deep enough, this time, to have accumulated in drifts, and the top level is still pristine, no contamination with limestone dust.

Merrin is going to have a SNOWBALL FIGHT nope, sorry, Imaginary Kalorm, but having a snowball fight with her imaginary friends who live in her head is too silly. But she IS going to spend the next three hours filling her collapsible tub with snow, hauling it back, and turning on her electric heating element just long enough to convert an entire 100L tub of snow into a quantity of water that fits in a pot, dumping it into her cistern, and immediately taking the tub out again.

She burns almost 1000 Wh of stored battery power, between her suit for all that chilly early-morning physical labor and the cooking element to speed up melting the snow (because she has nowhere to PUT a giant pile of snow to reliably capture all the water once it melts in the sun), but she also gets an entire ten liters of water.

Merrin! Is going! To give herself a sponge bath! (Later, once it’s warm.)

It feels like the absolute height of luxury. 

(The imaginary voice of her mom pipes up unasked-for to fret about how low Merrin’s standards have gotten and how this is evidence that she cannot possibly be very okay. But imaginary Kalorm gets it. And imaginary Laeirthe from her fanfiction thinks it’s really quite sensible and valid to find her joy where she can, because her morale and emotional stability are among her top genuine resource constraints.)

Merrin suspects that she’s not, in fact, super okay. Isolation is psychologically bad for humans, and the gnawing constant threat of slow starvation and approaching unsurvivable weather has got to be bad for her, and her lovely win-win situation with her stress-relief boyfriends is a thing of the past, and probably the only reason she’s not COMPLETELY falling apart is that she’s too busy surviving to have time for it.

And the physical exertion is good for her mood stability, there is that. And she’s genuinely looking forward to her next 25-hour ocean expedition. 

And when it gets tempting, lying awake during the shortening but still stupidly long nights, to start having angsty doom spirals about how her existence as a person is meaningless if there’s no Civilization around her to contribute to, imaginary Kalorm and imaginary Laeirthe both make SUCH dubious imaginary faces, even though on all the other topics they rarely agree.

Whatever. Maybe nothing means anything when her actions affect no one but herself, but maybe the entire concept of “meaning” “something” isn’t even coherent. 

She’s going to make an awesome cave house and an awesome doompunk sun-robe and she doesn’t, actually, have to care if it “objectively” “means” “anything” to have done it.

Merrin finished sketching her designs for the doompunk bandage robe and the cave house ceiling. She can get started more easily on the former; for the latter, she needs to scheme how to carry more stuff back from her ocean trip, so she can harvest enough of the three different subspecies of strapwrack and the sailweed - which, it turns out, dries with a texture like waxed paper, and is pretty close to waterproof. 

High tide arrives at 33:45, 13 hours before sunset, in the heat of the afternoon. The temperature peaks at 32 C and 70% relative humidity. 

The front of the cave, directly under the tarp, gets up to 25 C, which at 70% humidity is enough to feel kind of gross, but at the back there’s a faint waft of a draft from the connection to the deeper caves. And the radiation sensor from her medical diagnostic kit, set up as a fixture beside it, is silent. Radon gas is heavier than air and tends to trickle downward, not up. 

Merrin sits by her cooling vent and sews bandages and wonders about enlarging the opening and setting up some kind of electric fan. Motors aren’t difficult. 

Orrrrr she could be lazy, and sacrifice her portable ventilator, which is one piece of medical equipment she cannot IMAGINE needing. If she has a medical problem of that level of severity, she's...basically just dead. And it's already designed to be really power-efficient for moving air around a circuit, and it has built-in air filtering.

All she has to do is muck around with the tubing to dissect the circuit, and then go dig around in the software until she figures out how to rip out all of the alarm settings that are trying to scream about how something is terribly wrong and she needs to check on her patient right this second. And then make another meter of wire-and-plastic pipe to hang down the cave, then take the end of the circuit that should be going into the patient's lungs and instead make it pump air into a big round strapwrack basket covered with plastic sheeting with a lot of small holes in it, so that the cool air is coming out diffusely at a bunch of angles and not just, like, intense direct puffs of it. And drill a climbing piton into the back of her cave and hangs up her ventilation globe at chest-height. ....And use one of her modular interoperable medical-equipment-automation-loop connection thingies to make the radiation sensor talk to the ventilator and shut it off if there's a radiation alarm so it doesn't just pump her cave full of radon gas while she's too far away to hear the alarm going off. 

...All right, fine, that was in fact not obviously fewer hours of work than just making a motor. But, consider: it's really awesome. 

She can't afford to run it around the clock. It might be ridiculously power-efficient, especially when it's moving air against minimal resistance because there is not, in fact, a patient connected, but it still draws 75 W. She's looking to be on track to get, like, 1350 Wh today on the solar panels, she lost some morning hours to a cloudy sky but they were the really low-productivity early morning hours anyway. 

But she can afford it until it starts to cool down, and hotter days will also correlate with higher solar power... 

True low tide won't be until, like, six hours after sunset, according to her graph, but it doesn't take nearly that long for her nearby tidal flats to be exposed. And by 40:00, the outside temperature is already on its way back down, with a nice ocean breeze blowing in. 

...Merrin is on track to eat another four of her dwindling meal bars today and not necessarily get enough calories; she's eating local biomass, and it's not making her obviously sick, but she doesn't really have enough of it to make up for a 2400-calorie deficit. 

Also: she's bored. She took a two-hour nap in there at some point and doesn't super feel like she needs another yet. She wants to be up and moving. Not in her suit. 

She's going to go for a walk by the tidal flats, she decides, and take her sugar and protein test strips and her handheld X-ray spectrometer. Possibly peek in the danger cave; she ended up not using the danger tidepool for this harvest, because she didn't bring back that many live-catch animals and did not even slightly budget energy for making a cage for them. She'll make a note to do that tomorrow, Day 11, so it's ready at the end of her Day 12 trip. ...Also she'd need her armor to cross the river, so she'll skip the danger cave today. She really wants to at least feel the breeze on her skin, even if she can't safely take off her head covering and lift her face to feel the warmth of the sun. 

(It continues to be weirdly tempting to sunbathe on this planet even though this is a terrible idea.) 

...You know, Merrin is actually very curious what's inside the weird blobby-sac plant. She initially parsed it as another biofilm but it's more structured than that. 

If she cuts one open she could have a look. Maybe it's somehow edible? 

(It smells good. And she's really really hungry.) 

It really smells like it should be edible! It's incredibly tempting to stick her tongue in it. 

Merrin is not that stupid. She brought a bunch of sample bags, and she manages to catch most of the syrupy contents before they spill out onto the rock, and then she finds a drier spot to sit down and she dips some test strips in it. 

Very faint positive for protein on the urinalysis strip. 

STRONG positive for glucose on the non-selective strip. Like, off the top of the scale that her handheld analyzer can read, it's just giving her FLAG: OUT OF RANGE HIGH. 

...Also a pretty strong positive for glucose on the highly specific strip, too. 

THESE PLANTS ARE FULL OF SUGAR GOO AND MERRIN WANTS IT IN HER FACE RIGHT NOW

Merrin is going to exert great self-control and not eat the sugar goo until she's cultured her gut bacteria on it and done all the other tests she can think of, and then she's going to start with a tiny taste, and see.  

...She has a surprisingly good feeling about it, though? It's occurring to her that a plant under strong evolutionary pressure to avoid freezing during random frequent temperature drops could, rather than filling itself with toxic antifreeze compounds, just...be full of sugar. Sugar syrup has a significantly lower freezing point than water, and the plant can use it for energy storage. It'll increase the osmotic pressure inside the bulb, allowing it to suck moisture in even from the salty seawater and then hold onto it as long as possible. 

And there aren't any complex structures in there. The skin is almost certainly inedible – though she's going to take it in case it can be ground up for pigment to paint her AWESOME DOOMPUNK SUN ROBE – but she wonders if there are even any living cells in the syrup reservoir. Maybe not! In which case it doesn't harm the plant if it forms tiny ice crystals or gets really hot in the sun, and so the plant would not necessarily be under selection pressure to waste energy on any more complicated proteins that could be toxic to Merrin. 

...She's not going to do better than this with another hour down here. Merrin heads back up with her find, to start the tests. 

It's not until she's back at camp that she realizes she just walked all the way up the river-channel bank and is barely winded. Well, it makes sense, she'd been looking at a 10-planetary-day timeline to be properly acclimatized, but it's good to confirm.

Maybe she should run a complete blood count on herself and see what her hematocrit is up to, not because there's anything she can do about it one way or another but she CAN and she's curious... 

Day 11. Evening. 

Merrin's gut bacteria love the Bladdersac syrup. She can't detect any uranium in it, or any other accumulation of toxic elements. Judging by the composition under the spectrometer, it's probably 70% water and 30% simple molecules with carbon and hydrogen and oxygen in them, though since of course water is also hydrogen and oxygen it's a bit of a handwavy interpretation about the ratios of things and she has no real way of telling what kind of sugar molecules are in there. 

It tastes powerfully sweet. 

She does not suffer any ill effects from a 2g serving of it. 

Or a 20g serving. That goes fine! It's delicious! 

However, come evening, she is regretting her rapid conclusion that it was nontoxic and her resulting decision to eat like 150g of it with the very last of her previous deeper-sea harvest.

She's pretty sure that her gut cannot actually absorb all of what's in there - there are plenty of sugar alcohols that taste really sweet, but aren't digestible - and her gut bacteria are probably having the best day of their lives, and also undigested sugar is a great way to pull water back into the gut, and in short, Merrin had in fact been having a constipation problem after the equivalent of weeks of dehydration and only eating compact meal bar rations, and she is. Not having that problem anymore. 

It sure would be nice if her past self had in any way prioritized toilet facilities. She didn't, because as mentioned it was not a problem very frequently or urgently before, and so tonight she's going to be making several hurried trips out of her cave, in the dark and increasing cold, to do her business somewhere nice and far away from her house. 

At least it definitely seems to be nontoxic. And she got some rapid-energy calories from it, she felt great until the GI side effects kicked in. 

Eh. It'll be a good sweetener to make her incredibly boring diet of snails and seaweed pith more palatable. And at least she got her harvest-storage cage ready for tomorrow before the side effects hit her. 

Her sleep is pretty interrupted for the first twelve hours of the night, but fortunately there's still way more night left, and she'll manage to be plenty well-rested by morning. 

Sunrise arrives at 17:18. The night is already 90 minutes shorter than when she arrived. The low-point temperature - garnered from a portable sensor Merrin is leaving outside and syncing data from once a day - is only -36° C.

The tide is visibly starting to turn by 18:30. 

Time for SAFETY CHECKLISTS!

And then to swim out to sea by daylight. She leaves at 21:30, three hours after high tide – it'll cut her time out at sea, and she doesn't want to leave it any longer, the outgoing tidal current will be more dangerous to swim in if the remaining water in the channel is only a meter or two deep.

(She does spend some of the transit trying to swim down in the permanently-submerged river channel, just to check if she could ride it out to sea without getting smashed into rocks. ...She comes away thinking this is nooooot obviously a good idea. The current is faster than it looks.)  

Merrin didn't use anywhere close to all her O2 on the last trip, and she had suit power to spare – and should need a tiny bit less today on heating, the top 50 cm of the water or so should actually warm up a bit. 

She can afford more swimming around underwater, she thinks, to categorize species more thoroughly and to enjoy the beauty of this planet by daylight.

The tide starts to turn at 37:15, sixteen hours after she swam out. The smaller tides go out less far than the larger tides, as well as not rising to as high a peak; there are visibly tidal-flat organisms still submerged, though Merrin avoids swimming too much in the shallow water where a sudden change of current might fling her violently into the rocks. 

The bore goes through at 44:19, 2.5 hours before sunset is due. 

Merrin swims back 45 minutes later. 

...Thaaaaat might have been rushing things. The current is still pretty turbulent and the water level in the channel is not quite as she would prefer for ease of avoiding obstacles. She could handle it fine unencumbered, but she’s carrying like 100 kg of plant and animal samples, stuffed into mesh bags and tied to herself with paracord. She is not currently graceful or streamlined.

She does not, in fact, think she wants to risk the more powerful tidal currents when the total tidal amplitude is LIKE TWENTY METERS MORE PROBABLY with the  moon-close-to-planet "spring" tides. She would have to swim even further out to stay in safely deep-enough water at extreme low tide, and that increases the odds of getting caught in a fast current that drags her ten kilometers out to sea unless she burns way too much suit-power on fighting it. 

Honestly, trying to get out of the water right as low tide is turning and walking the rest of the way might be faster. It’s a long way to walk, but it’s probably not seven hours of walking. But then she would have to carry 100 kg of sea life against gravity…

She does get in well before dark, and finds the energy in herself to slosh-swim her way into the half-flooded danger cave. Part of her prep involved drilling a couple  of climbing pitons into the stone, behind a protrusion to keep them out of the way, and coiling a fifty-foot paracord harness; it’s long enough to reach the danger tide pool, though at her brief visit the radioactivity levels were lower, the radon accumulation must get periodically washed away.

It turns out that there’s no current to speak of, though; the water is sloshing in, but has nowhere to drain out in significant volume at the other end, so: not much current.