Worldbuilding Prompt #798 - The Cave At World's End

This post was inspired by a writing prompt in the Worldbuilding Community - Worldbuilding Prompt #798 - The Cave

It is Part 3 of a series I'm calling "Asteroid Fall", all based on Worldbuilding prompts.
Part 1 was Worldbuilding Prompt #796 - A Tidal Wave To End A World
Part 2 was Worldbuilding Prompt #794 - The Asteroid's Secret

Enjoy !

Image created by AI in NightCafe Studio

"Mama, I'm cold..."

"Hush Jinna, we'll find a way to get you warm, but give us a little while, okay ?"

Tish had no idea how they'd find warmth here, but it was her family. They'd find a way.

She still didn't really understand how they'd survived. They heard the news of the incoming asteroid over The Splosh, as they called the planet-wide information network. But when the starships came to evacuate everyone, their floating homestead was too remote to reach a pickup point. They had their skim-boat all loaded up to try to make it anyway when the terrifying news had come through that the asteroid had sped up and was going to hit while the evacuation was still in progress.

All they could do was get into the survival pods strapped to their boat and hope for the best.

And this was what passed for the best.

The asteroid's impact had made tidal waves that swept over their homestead, swamping and smashing it. The skim-boat, too, had been torn to shreds as it's autopilot tried to navigate a wave crest the size of a mountain. The pods had clung together with electromagnetic tethers, and somehow all five of them were still alive.

So now they found themselves standing in an oceanside cave. A cave that hadn't been there before, on a world which had been entirely ocean until half a day ago. The endless ocean outside was turbulent and chaotically choppy, and the sky was stormy.

"Where did this cave come from, Biran ?" Tish asked her husband. He was still fiddling with the communicator, but the white noise coming from it conveyed the depressing reality that there was nothing wrong with it, it's just that no-one was there.

Biran shrugged. "I guess the rock broke up Aquatica's crust somehow. The last message I heard said it hit the other side of the world, near Splashdown. Perhaps the seabed was pushed up on the opposite side to the hit."

"What are we going to eat, mama ?" That was Kevel, their oldest son. The sensible one. Asking sensible questions without understanding how life-changing the answers would be.

After a few moments, Tish gave an answer that was intended to be reassuring. But she found that by thinking about it, perhaps it really was a practical solution.

"Well, I know the fluorescent seaweed in this cave. It's supposed to live a thousand metres down, but it'll take a few weeks to die off above water. It's edible if rinsed, and we've got water distillers in every survival pod. The seaweed will taste like spinach, sorry. But it's full of iron and vitamins that are good for you."

Abandoning the useless communicator, Biran added his thoughts to the discussion. "We've got a month's worth of dried rations in each pod, as well as blankets, solar heaters, tools and other useful bits and bobs. We can make a raft from the pods and catch fish."

Looking out at the stormy sea, he added "We might need to wait for that to calm down a bit, but I think the tsunamis are finished. And I can see driftwood and debris in the water we can pull out and bring back in here to make a shelter."

Biran put his arm around Tish. "We could be the last people left alive on Aquatica, and there's no guarantee anyone will come and rescue us. But we know this world and all it has to offer. We're pioneers and survivors."

"We won't just survive, we'll thrive here."