?????!!!!!

Was it not a full moon like two days ago???? 

...She does remember it not being all the way to full yet on the first day when she was doing all the frantic carrying and knew its rise meant the tide was around the turning point. She's been here...three and a half days, approaching four?

The moon sure seems to have traveled halfway-ish through its lunar month since she got here.

...A seven-day lunar month wouldn't even be that much shorter than dath ilan's lunar month, she reminds herself. That's, like, 18.5 dath ilani days, versus 28. And a shorter month makes sense if the moon is closer. It just feels weird in combination with the really long solar days. 

She watches the stars and finds things to productively think about for a while, and goes back inside and finds different things to less-productively daydream about while lying in her sleeping capsule – with the sleeping bag zipped, this time, the downside of ducking out in the middle of the night is that it cooled down while she wasn't in it.

At some point in there she hears the tidal bore wave crashing through, and writes the time down for her tidal-cycle calculations. 

And eventually she sleeps, and then it's the morning of the fifth day. 

Sunrise is six to eight minutes earlier than she would expect if the day were exactly the same length as yesterday.

The outside temperature is only down to -37° C; there was cloud cover during the night, it's blowing away now but still visible on the horizon, and at some point close to morning there was maybe even a bit of precipitation. There's snow on the ground. 

Enough snow to be worth running around to collect it and melt it for drinking water?????? 

Not really. It's a thin enough layer that it'll be pretty mixed with the omnipresent surface layer of limestone dust. 

Awww. Her drinking-water situation isn't dire right now, she got about 3 liters yesterday and she's not horrifically dehydrated on 3 liters per 64 hours, but that leaves exactly zero water for...anything else...including, like, properly washing her drinking bladder with soap so she's comfortable refilling it and can drink while in the armor without it being really inconvenient.  

Tide and moon status? 

Tide: on its way out. Not that high, there's quite a lot of stepped limestone river-channel-walls exposed and the top curve of the Danger Cave is visible, but...it might actually just be a small tide, rather than having hit high tide sooner than she would expect given the timing of the tidal bore? There's a visible high-watermark left by all the tiny pools of water that immediately froze in place. The moon is also still pretty high in the sky, which agrees with "not too many hours since high tide." 

Huh. The moon is already past its peak and the sun is only just rising, but the sun isn't opposite the moon, which would be what predicted a smaller-amplitude neap tide in dath ilan. Moon orbital eccentricity, maybe? It does possibly look a tiny bit smaller in the sky. 

Even wearing an emergency blanket like a cloak, the main cave space is still cold to work in. Time to retreat to her sleeping capsule and do MORE MATH. 

...Writing down her best recollection of tidal bore timing, high tide, and moonrise/moonset for the last four days, Merrin is able to make a shaky prediction that the lunar day is something like ten hours longer than the solar day. Somewhere between 73 and 76 hours probably? She's expecting low tide in...sixteen to eighteen hours? Early afternoon. And the next tidal bore in 21 to 25 hours, midafternoon, and high tide 12ish hours after that...

The time to go out to sea would be now, if she wanted to do that, but she's in fact not super ready. 

Hmm. The next high-tide-going-out window is awkwardly timed for the middle of the night - if high tide is 6-8 hours after dark, and she's right that it's a smallish tide, the swim-out-to-sea window would be several hours later, but...she could in fact be awake, if she goes to bed before sunset, which she will 100% absolutely be tired enough to do, and sets an alarm. She could have her suit fully charged if she doesn't use it too much today. Her suit has artificial lighting, and it can handle keeping her warm in 4° C water just fine. Low tide will probably be 18-19 hours after high tide, the bore will be 6-7 hours after that, and then she'll want to swim in once it's settled.

...If she's mathing it right that would still be some hours before dawn. She's in fact a little worried about finding the river channel again if it's dark and she's been thrown around a bunch by the powerful offshore intertidal currents. And she sure is going to get swept out to sea some distance, not necessarily in a straight line, if she swims down the river with the outgoing tide. But waiting until dawn would mean she was out at sea for more than 25 hours, and if she doesn't know which way to swim to stay nearby, she might be out at sea and multiple kilometers away and she's not, actually, sure how well she can navigate to a shore landmark that she won't ever have seen by daylight from that angle... 

If she could get directions back by GPS, or even verbal radio directions–

Wait. 

Merrin does not have a second person to hang out at her campsite and track her suit location to give her directions back.

But what she does have is an emergency radio beacon. 

It's no good for its intended purpose of calling a training sim short and summoning rescue, obviously. But it's a directional radio signal, and her suit has a radio, and her suit even has software for locking onto a directional radio beacon and using that for navigation. 

This might actually not be an incredibly stupid plan. 

...Assuming she has some extra battery power banked. She'll probably be coming back exhausted, with her suit nearly out of juice, to chilly morning temperatures, and her sleeping capsule won't be warm from overnight body heat. 

Well. She's got more than 2000 Wh now. And a day ahead that might be longer and hotter than yesterday. She'll see. 

...Going off yesterday's hourly temperature readouts from her suit, the outdoor temperature rose by 40 degrees in the first ten hours. The narrow window of the day when it's actually a tolerable temperature to be outside might, in fact, coincide with the tidal flats below being nicely exposed. They'll even dry out faster if they don't fully freeze and have to thaw first. 

She could take a nice little walk by the river. Without her suit on. She could maybe have a peek in the danger cave! ...Nevermind, that requires crossing the river. There's a different slightly less Danger cave further upstream but she probably doesn't want to take that long a hike on her first try doing even light activity with no supplementary O2. 

...Merrin does want to take a walk by the river. It sounds...nice. She'll be able to smell the sea and feel the breeze on her skin. 

She just might want to plan a separate suit expedition to peek in the cave. It's occurring to her that she might want to bring back, like, a lot of sea organisms, and then ideally she would keep them as live-catch in a tank, but she does not have a tank. However, the cave might well have tidepools, that are regularly refreshed by new seawater but don't rapidly heat up and evaporate into brine in the sun. If Merrin weaves a cage out of strapwrack, she might be able to secure it there and expect her captured critters to survive for a few days... 

Perfect! She has a plan!

The cold hours of the morning - though they're quite bright hours, the sky is perfectly clear again and her solar production is picking up nicely - go toward more sun-angle measurements, watching the tide continue going out, and Safety Checklists and logistics planning. 

She's going to have a very high mental workload during some critical parts, and so everything that she can possibly make easier - timekeeping, navigation, tracking her air and remaining batter charge - needs to be made easier, with automated reminders. This mostly involves plugging the general-purpose electronics screen and data-entry console into her suit and doing a whole bunch of incredibly annoying tweaks to the standard programming.

It is, again, something an eight-year-old could do. This does not mean that Merrin is enjoying the process. 

And then she thinks for a while about UV protection, for daytime activity not wearing her armor.

Her clothes will do it, for this morning's excursion – she can wear gloves, and head and eye coverings, and if she slathers her face and neck in sunscreen and is careful she probably won't get second-degree burns from an hour outside in the late morning sunlight – but they're also really not specced to last through years of regular super-high UV exposure.

And she's...sentimental...about them. She does not want them to fall apart from sun damage within a year. 

...Textiles made fully from local fibers are going to be. A long-term project. And spectacularly time-consuming, she can barely imagine it. 

But she does, also, have a quantity of medical supplies, including various types of bandages, that would be super reasonable for a big multi-casualty medical scenario lasting a few days, and is way more than she needs to keep in reserve for her own first aid if she has a Stupid Accident. They're lower-quality fibers than her actual clothing, since they're meant to be used once and disposed of, but she should totally be able to make a robe that will last through the planetary summer. If she survives until winter, she'll teach herself to spin and weave by feel in complete darkness and then she'll have something to DO WITH HERSELF during the long winter nights. 

And she can figure out how to extract pigments from local plants, and dye or paint her robe to make it extra UV-resistant. Also it'll probably look pretty cool! Arts and crafts!

10.5 hours after dawn, the temperature hits 4° C. 

Merrin puts down her tasks and dons all of the clothing she currently possesses, and a light backpack for treasure hunting any items she might collect and want to bring back with her, and to tote along a liter of drinking water. (Her still isn't producing yet but it probably will soon. She makes a mental note to think about dumping more seawater into the evaporation pan. 

Moving slowly and pacing herself, she walks down the limestone plain toward the sea. 

Her exertion tolerance is okay! The real test will be how many breaks Merrin has to take on her way back up the riverbank, but walking on mostly-flat ground, she's not noticeably out of breath even with the higher gravity, which she's more or less completely stopped noticing. 

Merrin keeps having the urge to take off her head covering and sunglasses so she can "feel the sun on her face". Which she absolutely shouldn't do! It just turns out that she finds being this covered up a bit claustrophobic, or confining, or something, even though really it should be strictly less claustrophobic than wearing her power armor all the time. 

Walking down the bank also isn't too bad! Her heart rate is up a bunch, but not in an unpleasant way, and she can tell that she's breathing faster and deeper but it's not feeling effortful.  

It's preeeeeeeeetty. 

(It smells really weird. Like the sea, but...not. But not unpleasant. If anything, there's an interesting almost-perfume-like fragrance rising from the various gloopy biofilms on the rocks.) 

....Merrin is maybe going to scrape some of it off and into a - she didn't bring a container - oh there's an empty, not-too-broken shell from a recently-dead mollusc-like organism, that must have been thrown all up and down the channel but has, however temporarily, been deposited here, before it would inevitably have been turned into sand... 

Merrin's UV-resistant painted bandagerobe is going to be SO DOOMPUNK it'll be amazing.