Spongelike organisms? Anemones? 

They're super cool but they don't look incredibly edible. At least, Merrin has never heard of anyone in dath ilan eating sea anemones? They kind of look like their tissues are mostly just water? 

...What's in that gap between two rocks? 

!!!!!!!!

Giant sea snails! They're huge! Probably a kilogram each! And they look nice and muscular, and pale-fleshed – no weird UV-protective pigments – and they'll be so easy to catch, they're grazers and they move very, very slowly. They're grazers, not filter-feeders, so less likely to end up full of accumulated heavy metals and algae toxins... 

On reflection she's going to come back to harvest them a bit later. They might die if they're tossed around in her mesh bag and exposed to the cold air at the surface all night, and if she can get them to shore alive then she can try stashing a few in her danger cave. 

(Merrin is, for some weird reason, now feeling oddly fond and possessive about the danger cave. It's her danger cave.) 

Also giant centipede-worm-fish! They're slower-moving than the centipedefish with paddlelimbs, they seem to be bottom-crawlers rather than swimmers. She can't tell at a glance what they eat; none of them are actively eating right now, they seem to be torpid. Probably worth harvesting one. They're spiky and look kind of intimidating to grab but she's literally in power armor, she will win a fight with a centipede-worm-fish even if it's the size of her arm and has spiky mouth pincer things. 

...And a lot of bivalve shells. They're slightly less thick and armored than the intertidal ones, and probably a lot less full of antifreeze, but they're also definitely filter-feeders. Worth harvesting, but she'll need to test them really carefully for safety. 

Time check: wow, it's only been, like, twenty minutes since she jumped into the river. She's got time to go deeper on this trip. 

(It's going to be a really, really long night) 

She's now more than two kilometers out from the shore. Approaching 60 meters of depth. 

The coral-like mounds from earlier have been replaced with forms that look a lot more like...coral. 

The fern-like lacy fronds are...probably plants? They're purple, albeit a much paler lavender-purple, and do not appear to have any way of taking in nutrients even as a filter-feeder. 

!!!!!!!!! 

Weird giant sail-leaf seaweed! It's longer and wider than Merrin is. 

Also! Bioluminescent six-eyed arthropod swimmer!!!!! This one is the size of Merrin's thigh. It looks like it might have significant meat on it!

....And further down. She's approaching 30 minutes, and 20 of those minutes were below 30 meters of depth, she should head back up soon and save her air for the harvest later. (It'll be a lot easier to do a round of harvesting samples when the tide is at its lowest point, the current is slackening as it turns around, and she's not having to swim or use suit power to stay in one place.) 

At around 70 meters of depth, the rocky slope...flattens out again. And stretches out as far as she can see. An endless plain, the ground thick with fallen sediment like snow; the fact that organic particles drifting down have a chance to settle and stay put hints that the water down here is much less disturbed by the violent tides above. The wild profusion of more delicate-looking ocean life hints at the same thing. 

Weird giant arthropod!!!!

...It admittedly looks like an enormous hassle to drag it back to shore alive. This one definitely has mandibles. It might chew its way out of the mesh bag. 

The other swimming creature is...probably...more similar to a jellyfish than an arthropod or a mollusk? It's more or less translucent. Merrin can directly see its organs. It's probably not very calorie-dense. 

....Waaaaaaait. 

Those aren't weirdly shaped rocks, are they.

Those are GIANT SEA SNAILS! They've got to weigh more than twenty kilograms each! 

...They're probably like a century old. Merrin might be able to figure it out by counting shell rings or something. 

No point harvesting one now; she'll need to test small samples first, and so she might as well start with their smaller relatives. And it...feels kind of bad...to kill something that's been growing for a century, even if it probably barely has a nervous system to speak of and almost certainly doesn't have, like, qualia. She'll do it, obviously, if the alternative is starvation, but...she doesn't want to do it and then waste most of it. 

And now it's time to swim up to the surface and....hang out. For, like, a pretty long time. 

The water is surprisingly placid, almost three kilometers from shore. Merrin can't actually see the shore, much; there's no artificial lighting on this planet, and apparently no mountains to stand out in silhouette from this distance; it all blends into the horizon. But she's locked onto the beacon again, from here. She's not lost. 

She leaves her helmet sealed, since she's not hungry or thirsty yet, and just floats with her head at the surface, so the suit intake vent for air filtering is nicely above the water surface. (It can handle intermittent splashing, the suit will only get mad at her if she tries to keep it on filter-external-air mode while fully immersed for more than ten seconds.) 

...Time check? Air check? Power check? 

She jumped into the river at 55 hours, 18 minutes since today's sunrise. She spent 38 minutes underwater. It's now 55 hours, 56 minutes since today's sunrise. 

She's down about 60L of oxygen – she was burning through it faster, while active and getting all of her O2 needs met like this. CO2 scrubbers are working well, and she has tons of capacity left; the zeolite cartridge lasts 12 hours in full closed-system underwater mode, and use minimal capacity in surface mode. (She has a second back at camp, to swap out, and eventually she will need to bake off all the CO2 at 200° C to reset them.) Her nitrogen storage capacity is a lot smaller, but she's not actually using it while underwater, just recirculating it; the only losses are when she unseals the helmet, and it's supposed to be good for, like, fifty rounds of that. 

Power: she's down to 1920 Wh on the battery; the underwater powered swimming mode is hungry, even if she was mostly gliding with the current rather than fighting it. She'll still burn a bunch of battery life just floating at the surface, on heating, but it should slow down a lot; even on pessimistic assumptions about rate of heat loss in 4° C water versus -40° C air, and how much swimming she has to do to avoid drifting ten kilometers out to sea, she would have almost 38 hours out here. Realistically she wants at least 200 Wh for the swim back, just in case the incoming-tide current is less helpful than she expects and she needs to swim actively, and she's going to be doing another set of dives to fill her harvest sacks and should budget like 150 Wh for that. But that still gives her 31 hours of heating-and-floating. 

The tidal bore is due.....in 23 hours. She'll want to wait it out a nice long way from shore, for an hour or so, and then swim up. 

.......Why did Merrin commit herself to 24 hours of floating in the ocean, again? She is going to be SO INCREDIBLY BORED and she can't even amuse herself with extra dives, she has to save her suit power. 

Merrin will stargaze, and try to make up and memorize more constellations. (She's using the suit camera only in photograph-mode, not video, and only occasionally; it doesn't use a lot of power, but she's being cautious.) 

She will WRITE FANFICTION IN HER HEAD about the constellations as imaginary characters. 

....You know, Merrin thinks to herself, Kalorm would really, really like this place. No Civilization with all of its rules and guardrails and systems. No tangled net of social expectations. Just - nature. Plants and animals with no agenda save their own biological survival and propagation. 

- that's a pretty oof thought, huh. 

Why? 

Because Merrin is really superheated lonely.

And...Merrin was happy, back home. She liked Civilization. Kalorm always found that sort of bemusing, on the handful of occasions after his hospital stay when they spent time together socially. He would poke and poke, and Merrin always found it hard to unpack why being, in fact, quite a different shape from what her surroundings expected, had never exactly bothered her. It can't be just because her misfit-ness is in areas that gave her some very powerful comparative advantages, because the same would absolutely be true of Kalorm if he even slightly tried to take advantage of his unusual areas of talent.

It's...some fundamental personality difference, between the two of them. And that's interesting, right, because - Kalorm might be lonely too, here, he did often choose to wander the limited wilderness of dath ilan with friends and not completely alone, but - Merrin thinks he would consider it worth it for the - what - for the freedom. For the lack of guardrails. For nothing and no one trying to steer him into a tidy little box for system-level efficiency, or to weave a more nebulous web made of things like "risking True Death all the time for fun makes your parents sad." 

...And Merrin - isn't, really, like that. The world is made of tradeoffs, between freedom-from-expectations and...approval, usefulness, being a small part of something larger than herself. And she liked the second thing, and so she would not, in fact, have chosen on purpose to end up alone on an exoplanet, locked in a contest for survival against the cold uncaring laws of physics.

…But she is here, and - it’s not actually true that she has no understanding of Kalorm’s deal. In some ways he makes more sense to her than most people do.

Kalorm would think her survival so far was really cool.

She'll never have a chance to tell him about it. 

But...it helps, actually, to imagine the hypothetical conversation. She mostly has pretty clear predictions of what he would say, and...she's still talking to herself in her own head, and not another actual human being, but it still feels like it fills up some of the staticky blankness in the social-modeling cognitive areas of her brain. 

It's...possibly kind of vaguely psychosis-adjacent, to be talking to imaginary people in her head. 

But you know what Kalorm would say to that: fuck that shit, it's literally nobody's business but her own what she does with her brain. She can't hurt anyone but herself, here, and hurting herself is her own superheated business. Nothing she can possibly do can ever harm the fabric of Civilization, because she's been completely and permanently causally isolated from dath ilan, and...that's freedom. That's a kind of freedom that Kalorm will never have in dath ilan.