Best way to explore?

[Winter Eclipse]

So I'm still trying to figure things out and one thing I always struggle with is trying to find anything farther than the starting area and just digging a tunnel down into the earth seems to take forever, is that the best way or is there a better way of going about it?

[Yodarkore]

either debug mode (look on official ONI forum for more infos on how to) or yes, tunnel digging (2 step high, put some electricity in it for some alga oxidezer here and there and a few air scrubber too when needed, and sometime an outhouse to avoid long back trip for poo duty)

[Yodarkore]

And also a wash bassin too when crossing slime biomes, and ore scrubber when available, it helps a lot avoiding spreading germs into your base.

[Prophet_01]

Up or down is usually faster (less material to dig for a given distance). But as I try to avoid slime and gas contaminations like the plague, I end up going for all directions at the same time (while grabbing all the abyssalite, wolframite and goldamalgam I can get).

Knowing the biomes around your starting point is usually enough to narrow things down a bit. I'd start with that. Though it rly depends on what you are looking for.
Especially with geysers, you rly want the closest one and not necessarily the first one you find. So searching in all directions is kinda important.

[Varenvel The Festive Dinosaur]

making just 2x2 tunnels to sides is not bad and down just 1x1 , just avoid pockets with slime lung

[PhailRaptor]

I usually scout along the veins of Abyssalite between the biomes. Not only does this minimize your risk of contamination from Slimelung and P-O2, it also preserves the biomes themselves, due to the properties of Abyssalite. You won't have a Heat Biome melt it's way through a Cold Biome after you dig your tunnel through, for example. It also gives you tons and tons AND TONS of Abyssalite to build with, something that is very useful given it's almost complete resistance to heat transfer.

[Varenvel The Festive Dinosaur]

Originally posted by PhailRaptor:

I usually scout along the veins of Abyssalite between the biomes. Not only does this minimize your risk of contamination from Slimelung and P-O2, it also preserves the biomes themselves, due to the properties of Abyssalite. You won't have a Heat Biome melt it's way through a Cold Biome after you dig your tunnel through, for example. It also gives you tons and tons AND TONS of Abyssalite to build with, something that is very useful given it's almost complete resistance to heat transfer.

i usualy do same , it makes you avoid chlorine and hydrogen as well slimelung who all of these is best to be avoided early on

[CoyoteTraveller]

Horizontal is always way faster than up or down, because you don't have to wait for materials. If you are doing a ladder though, putting a material stockpile right next to it should help. Slime and PO2 (and other) contamination when going horizontal isn't actually a huge deal, it seems to be absolutely minimal if you add a couple airlocks spaced one tile apart, with an air freshener if you're paranoid. (A wash basin on the exit is still good.) If you're worried when going up or down, you can make your tunnel jog sideways for three tiles to do those airlocks, or even set up a 'sink trap' where your tunnel briefly switches vertical direction to catch hydrogen/CO2. That works when you're going horizontal too; any gas that goes down a three-tile dip is not likely to come up the other side.

Since mining out new areas is almost always going to be underpressured, you can run an oxygen vent down your tunnel easily and cheaply, maybe put a valve on it. You don't need a big air pocket to be make it much more traversable, and you can stick it behind an airlock, or above/below your tunnel in the case of hydrogen/CO2, to keep it in place if that's a problem.

I was way more paranoid about slimelung than I should have been while I was new to the game; I've never had any actual problems with it and for mining, I think you can pretty much set up a washbasin and then ignore it. If you have a choice though, it's better to go through literally any other gas than PO2, since your dupes can hold their breath in there with no problems, and it's easier to control other gases since they go to one place instead of distributing throughout your base. You certainly don't need to purify anything within your mining tunnels though. The only thing you need to avoid at all costs is liquid (so always leave two tiles above your tunnel between you and a lake).