Without going into details on plot and keep it spoiler free can say:

a) best locations are where you can easily reach 3-4 different bomes with relative ease, so scout a lot and find a spot that also has a nice view (you will be seeing it a lot)

b) have plenty of space to "grow", your initial base may change a lot as you progress....there is plenty of stuff that is additive to your current base and its interesting to try it out and expand.

c) give it purpose, by having a clear idea of what you want out of your base...a place to sleep, to re-supply, or manufacture, or sit and relax. Function guides design.

I normally build my base in the lilypad zone near the entrance to Marg’s base, the deep lily zone, and the Crystal Caves. I’m also building a base at the edge of the void out of spite.

I built mine on the edge of the purple vents and the volcanic biomes, near the delta station. There is a ton of resources of every type in close proximity and not very deep either. Plus you can track the Chelicerate with the scanner room. Also close proximity to everything else on the map since it's kind of a central location on the map.

I like building on lillypads and have moonpool be under water

Built mine in the Purple Vents below the Chelicerate.

I built a medium-sized base 300 ms south of Delta station dock above a drop into deeper Twisty Bridges, mostly because I take lots of round trips and it's decently close to a lot of resources. I have another similar-sized base at the starting area of Glacial Basin (the one near the Seatruck docks).

I also have a teeny tiny base (one X-connector + scanner room) above some bigger rocks in the Lilypads, because damn that biome is MASSIVE and it's a pain collecting the fragments. I used to go there for ruby but not since I built a fully-upgraded Prawn.

Edge of the BK Trench is my favorite spot.

Very easy access to all resources. Lost River and thermal power nearby.

Just… don’t go too far north.

I normally build in the sw grassy plateaus or the nw mushroom forest

I usually just make a cyclops into my base.

Blood kelp trench (option 3) ftw

I’ve built at spot 2! Near the blood Kelp and those two mountains near the floating islands is a good outpost imo, but I struggled with materials a small bit. My main base was elsewhere. The locals are nice, you’re not far from the shallows, not far from the deep end.

It’s a good spot for later game play with quick access to relevant areas. >!The cyclops has a path into the LR!< near that area, but I’ve never personally >!driven my cyclops into the lost river through that tunnel thanks to the Friend outside it!<

I really like setting my deep base up at either the tree of life or the waterfalls entering lost river near the ghost leviathan.

I don't know where you should set up your base, but I now where you SHOULDN'T, please, DON'T PUT YOUR HOUSE IN CRAB FIELD

Grassy Plateaus, although basic is convienent. Go to the beacon for the 200m Degasi Base, and go a little south, near the border of (I think) the crag field. Theres an extremely pretty cave system there that can make for an excellent base. Theres also one near the blood kelp trench, which could prove useful later and is close to the sea readers path and other areas. (can send screenshots later if you need)

The Bulb Zone, although far from everything can be a good late game base due to it's relative safety (ampeels are chill if you give them their space, and bonesharks can be dealt with easily), titanium outcrops, thermal vents and lost river entrance. It's also pretty and has food sources nearby in the form of bulb bushes. If you have a cyclops (or when you get one) park it in shallower waters to prevent ampeels from attacking it.

Either of the mushroom forests (I prefer the NW mushroom forest) are pretty good. Easy access to the center of the map and the later game areas, whilst being pretty to look at. It's proximity to the blood kelp, underwater islands, bulb zone, shallows and other areas makes it a good hub spot. It looks cool too, and can be placed near purple pinecones for a flex or smth.

The sparse reef, although not pretty is resource rich and slightly close to later game areas, although its not one i'd recommend for a main base, and is pretty ugly tbh. Not a good place for a main base, but if you need resources build a scanner room and a small I beam or smth.

Jellyshroom caves are honestly really good. Get rid of crabsnakes if they annoy you, build a base and you're good. Shale outcrops, magnetite and lithium are all nearby, along with a good view and proximity to several other biomes.

My base is currently on the edge of the grassy plateaus, resting on the border of the blood kelp zone, underwater islands, and the mushroom forest. Great practical and environmental benefit.

Tree cove in lost river is my go to base location

On the ledge right before the Tree in the lost river. It gives easy access to thermal vents and an area in the lost river that has pretty much all of the materials you'll need (aside from creepvine, so plant some). Additionally it is extremely close to an end game teleporter.

Between the grassy plateau and kelp forest, almost on top of the Jellyshroom cave, for my main. The cove tree, close to the lava zone drop off for my secondary.

I got my base in the Grand Reef right next to the kelp forest that touches it. It's absolutely beautiful and there's no hostile creatures near it

My first base was right next to gasopods at the very edge of Safe Shallows. I liked the spot a lot. Close to the center of the map, lots of sunlight, lots of resources, chill, and shallow enough to have solar panels above the surface.

My other base was by the Great Cove Tree at around 900m and it was priceless for the endgame.

There is a thermal vent off to the right of the aurora. It’s close to the escape pod at the beginning of the game. I built a grain silo type base right in the middle of the vent, and a moon pool off to the side. It’s probably like 200m away max from the escape pod. Great early base, and it’s near a lot of late game stuff if you know where the deep entrances are.

But also, multiple bases works. And the big submarine is excellent.

I put mine in the red grassy area next to the Jellyshroom caves. It's a reasonable distance from the starter area, kelp forest, and blood kelp forest. The Jellyshroom caves are loaded with magnetite, too. And they're pretty :)

I always build my first base right at the escape pod. Then I build mini bases the deeper I go.

My favorite spot down below is at the gargantuan leviathan skeleton, it’s kind of a cross roads where you can go anywhere down there.

Bulb zone is pretty good for many different resources.

Jellyshroom caves for specialist resources like Magnetite and Lithium

Mountain island is front of the floating Islands, 50 meters deep there's this flat space where your base would fit perfectly, you'll be able to hear the reaper on the other side of the island without a single threat and also you get the obscene amount of lithium/black stone that the island keep spawning.

My first and best base was there and still has a place in my heart.

Above the cave entrance that leads you to the digassi base in jellyshroom cave, can get close access to 4 biomes

I positioned mine atop the cliff right in between all the biomes, with two moonpools hanging over the edge above the cave, looks epic

I like the Cove Tree. It's pretty, has no enemies, full of resources, and exits into the Inactive Lava Zone, Blood Kelp Zone, and Grand Reef.

On the rear side of the Aurora 😏

No! Sorry! This sub has used them all up. Oh well.

I built right by the life pod and have not felt the need to build another or anywhere else

I only ever did one pmaythrough of BZ. And I chose to do it ontop of a few of the floating islands near outpost zero. Huge mistake, because it was far from basically everything besides late-late game story elements. My advice would be to build somewhere around delta island, as its close to everything early to mid-game, and a bit far from only the very last parts of the game.

The map is small enough you could build in any place and be fine for the most part, I built by the lifepod and had no trouble prawn suit walking to anywhere.

If you wanna minmax, delta island is probably the best most central spot that has plenty of nearby resources and is relatively safe once you get any vehicle (especially prawn suit) and you’d only really need to go to the northwest once or twice so it’s not essential to be near there

The most work I did was border of the Grey and purple vents near the chicky. But I e mentally settle in the eye jelly zone because I liked the mild attention, until I found they can clip in and tag me.

For BZ, I built above the lily pad crevice. Basically above the big floating rock where the pilots last known location is. It was only the second base I built. The first was in the shallows. It was the perfect forward outpost for mid to late game stuff, a great location to push the plot forward.

The upper area near the lily pads themselves are pretty safe, you gotta deal with some glo whales, and the occasional lillypadder I usually hit with my truck.

But a great location for resources, and you’re really not that far from delta island which I use as my main landmark (free beacon may as well use it). It’s also pretty close to some of the deeper biomes you’ll have to visit.

Last Known Location in Lilypads hands down

You can cultivate creepvine outside of your base so no need to stick around the starting zone just to get close to the creepvines.

Twisty bridges - shallowsxs- thermal vent is the optimal crossroad for a base. as yo figured it out already.

Another nice, but not so optimal location is imho is the lilypad - purple vent border between the two mercury segment: huge open space to expand, nice view for the glowwhales and the floating lilypad rocks, around 100m depth but the solar panels still working, so no need to find, craft alternative powersource. con: most of th resourcer ar far away, like titanium and lead, but this isn't an optimal location, just nice.

Try on the ridges over by the Vent Gardens. Maybe even a Chelicerate observatory

next to twisty bridges

I had a really nice base that I built down in the purple crystal caves. It was right over a crevasse. So I had rooms on either side of the crevasse and one large room suspended over it. I could drive my sea truck under my base. I used the control room to change the color so that it perfectly matched the crystals around it.

There's a ton of resources down there, and you can use external grow beds to culture most anything you might need. The only resource that's a pain is table coral. So stock up on those.

Once I had established the start of a base I needed indoor plants, but it was always so slow for me to get to that base from the surface. I was concerned about plants spoiling before I got them to my deep base. So I parked my sea truck with it's teleport module there. Then I swam to the surface with my sea glide. Once I stocked up, I teleported home instantly. It's the longest jump I've ever done.

The Leviathan down there makes for creepy background noise. He's mostly harmless so long as you're careful.