No, irl you swim slow as hell. First stalker or sandshark you come accross would be the end of you, never mind a reaper

Not for very long. This is born out by shipwrecks. Without others around, and no tech, you die within a few years max. The problem is almost any injury or disease is fatal. Just being sick and unable to move for three days is a death sentence as you die of dehydration.

And that presumes you have the skills needed to survive, and at least basic tools. But you said no tech and almost none of us have the skills.

And that presumes you're perfectly healthy at the start. Glasses? Contacts? Medications? All of those go away. Most of us have something like that in our lives, or will in time. In centuries past we died, often painfully, which is what would happen here.

And that presumes you land on the islands. If you have to swim there, you'll probably die before you reach land.

Those are just the reasons off the top of my head for why no one survives that for very long.

For the sake of accuracy I feel I should point out that no matter what happens or how quickly the biome turns lethal for you, you will still survive for the rest of your life.

I would die by those stupid exploding fish

I would probably die. Without at least a working seaglide, I'm pretty much stuck on the island, as I cannot swim fast, long, or deep enough to explore further. Faced with any of the aggressive fauna, I'm pretty much doomed.

We know from the recordings that the Degasi survivors found the island challenging due to weather, and that growing enough food for all three of them wasn't possible. We also see the island base is damaged by a landslide, so we can say the weather can get pretty rough. But maybe I could eek out a living with what Bart left, assuming there's enough capacity to support food for one person. I have rudimentary gardening skills and presumably the grow beds make that a bit easier.

Pretty much I know my limits. I lack the tenacity or survival skills of Marguerit (she fought a Reaper solo), the perfectly-aligned education of Bart (they'd have starved without him, and figured out what Kharaa was), or well, Paul's... er... leadership (he was completely useless). I'm not skilled or fit enough to do any better than them, besides maybe Paul if he were solo.

Me? God no. I need fresh water.

I think it may actually be easy, but your initial survival will depend on where you land. I think you would definitely have a better chance at survival on the floating island, because of the Degasi bases and you could theoretically use their broken tech to help. Plus, the rooms are re-built. There is a good amount of food on the floating island, and it can easily be regrown. There are plenty of resources and the only issue is the crawlers. However, if you can get a weapon, you can kill them or jump in the water to evade them.

In the mountain island, it is a lot more dangerous and there is much less resources/food. But there is the precursor base, and a tablet that you can use to open the forcefield. If you manage to find the portal (it will be dangerous there are enemies in its cave) you could then go to the floating island and have the best of both worlds. I guess you could build a boat?

On the floating island? Honestly I think I could survive for a good while. There's food and extra water laying around.

But if I tried to swim literally anywhere it would be a death sentence, so I would probably die after running out of clean water.

Can’t sleep… cave crawlers will eat me…

Nah, I can't swim and would go batshit insane from lack of people

No probably not. It’s an alien planet. There’s a good chance your body wouldn’t even be able to process any of the creatures as nutrients if you tried to eat them. You’d also probably be susceptible to alien microbes.

The floating island is falling apart and going to sink soon, not to mention it gets terrible storms at some point in the season. So its out of the question.

I'm dubious the enforcement tower island has enough resources

Either island should be fine - there's usable shelter as well as plentiful food and water on both. The crawlers would be the only annoyance.

are we from our time? that's my theory as to why Ryley can swim so fast and be practically superhuman is because of genetic modification and stuff

I would not survive the initial impact that stranded me in the crater in the first place. My rib popped out when I bent over to get something out from under my bed 2 weeks ago.

Nope. I doubt I would last a week with my thalassaphobia. Only reason why I can play subnautica is the sonar mods.

Nope.

I live on an island IRL. So, possibly. BZ might beat me due to cold, but S1... Maybe.

I believe it would be possible to survive on the islands for a bit, but not long term.

1. Storms. IIRC, the lore is that the crater area has a dry season and a rainy season. Riley's adventure takes place during the dry season. During the rainy season, the Degrassi crew found out that it's unsafe to live on the islands full time as during the rainy season, it's like being at Ground Zero for a hurricane landing. That's why they moved to the Jellyshroom Cave.

2. Diet. If you lived on the islands, you should definitely get your fruit and vegetable dietary needs met, as there is plenty of sunlight and room to grow things.

The Floating Island has little fish living around it, so if you live there, you will NOT get your protein needs met by fishing alone. You will experience the problems that happen without enough protein in your diet, which will make it harder for you to swim, which means you will have a harder time leaving the Floating Island. Bart's farm should still be mostly intact, so you will just have to do basic maintenance on it.

The Mountain Island has plenty of fish around it, so you will be able to eat your fill of those, and you will have enough space to put grow beds everywhere.

1. Reapers. I know the song says to not fear the reaper, but you SHOULD. The Mountains are crawling with them, so you will have a hard time not getting eaten if you decide to dip your toes into the water if you stay at Mountain Island.

2. Building supplies. The Floating Island and the Sparse Reef have little building supplies, so you will have a hard time building a decent base. This also means you will have a hard time building a base with an Alien Containment unit so that you can raise your own fish to get those protein needs met.

Mountain Island has more building supplies, but a lot of them are guarded by reapers, and the reapers will not share.

1. Medical issues. Random horrifying medical problems will happen and you may die without medical help. Good luck getting your appendix out on planet 4546B! You will be unable to get a lot of the medical needs you already have met, so no glasses and no medications. You may get injured and die from the infection. However, if you are already healthy, your survival likelihood will go WAY up.

2. The Bends. I've been scuba diving in real life on multiple occasions. In real life, scuba diving is dangerous due to something called the bends, where gasses in your blood build up and rebel against you if you try to increase your altitude too quickly. This will harm you and can even kill you. Subnautica does not have this mechanism, and it would be a MUCH slower and more dangerous game if it did. This would make gathering resources for your bases much harder if if you were stranded on planet 4546B in real life.

With those points named, if you still want to try to live on the islands, here are two strategies I think would work.

Strategy 1: Floating Island Nomad

Using your Seaglide or a Seamoth, you transport enough materials to the Floating Island to build a nice base with an Alien Contaiment unit to raise fish. You live there most of the year.

You also build another base underwater that's not TOO far away from your main base. It must be at least 90 meters below the surface, as waves and currents caused by hurricanes on the surface won't affect you below that depth. I would recommend going to hang out with the Sea Treaders, as there are plenty of edible fish, interesting views, building supplies, and no predators (as Khaara is gone, the warpers won't hunt you).

During most of the year, you live on the Floating Island. As soon as it's rainy season time, you go to your underwater base and live there until the rainy season is over.

Strategy 2: Inside The Quarantine Enforcement Platform

You build a habitat, complete with a garden for fruit and vegetables and an Alien Containment unit for protein, INSIDE of the the Quaratine Enforcement Platform. This means you won't have to worry about the hurricanes, as you are in a secure stable location. During most of the year, you can eat fruit growing on the island's surface and fish from the shore. If someone appears to rescue you, you are in a perfect pickup location.

The problem is getting enough building materials onto Mountain Island. You will need a lot of titanium and quartz for this. You will need to leave the island to get it, because it's not there. If you go into the water, a reaper might eat you. However, once you build your base, you are safe and won't need to ever leave the island.

I highly doubt it without SOME sort of working technology to leverage. Assuming you made it to the floating island(the safer of the two options), all the possible shelters are in various states of disrepair and you have no way of fixing them. Which means either the crawlers will get you since you can't stop them from getting in, or the weather will kill you eventually because you can't do anything to mitigate it. And you can't construct anything new.

Food, in theory, you could grow but you would probably need some sort of tools to work the grow beds, to harvest seeds, till the soil, water them somehow. Food, without a fabricator, would at best be scarce. You'd have to supplement the yield from the grow beds, both to stretch out your resources and to get all the nutrients you need since the fruits and veggies won't provide it all. But how do you fish safely? Assuming you manage that, how do you clean and process the fish? Store it?

You could macgyver solutions for a while but at some point, probably within a month or two at most, the lack of functional technology would catch up with you and doom you.

Just my personal opinion.

No tech? That means you can only swim at the surface and have no way to make fresh water reliably. You can’t see the islands to swim there. Your best bet would be to swim to the Aurora and walk around it until you can find an entrance, hopefully kill the crabs, and get in to repair some of the basic functions. So probably not.

Now, stranded on the island itself, with a functional Degasi base and some way to kill the crabs? Sure. Plenty of food and water, shelter provided. Pretty close to a dream retirement for me.

if a determined Ryley Robinson was coming then I can surive. U can't sustain yourself for long on the island

My first playthrough I died bc I couldnt figure out how to get fresh water. Sooo, Id most likely die.