Oh well to get the coordinates you have to have the map the y coordinate is the one that shows what level your on and you usually spawn with a map but if you didnt all you have to have is silver paper and redstone which isnt to hard to get I hope that helped.
How do you guys figure out what level you are? X,Y, or Z. And I just cave/TNT mine. I know it's a little unpredictable, but I just expose alot of diamond veins while I'm at it. IN 2 minecraft days, I got meself 47 Diamonds.
As said above the middle coordinate at the top of your map is the elevation. bedrock is 0 and the ocean water level is typically around 65. There is no negative for the elevation coordinate. Or you can count up from bedrock.
I think, I don't do TNT mining, that TNT mining will destroy a percentage of the blocks mined. There is also the chance of lossing blocks to lava.
As said above the middle coordinate at the top of your map is the elevation. bedrock is 0 and the ocean water level is typically around 65. There is no negative for the elevation coordinate. Or you can count up from bedrock.
I think, I don't do TNT mining, that TNT mining will destroy a percentage of the blocks mined. There is also the chance of lossing blocks to lava.