https://minecraft.gamepedia.com/Obsidian#Obtaining base for an unenchanted diamond pick [Obsidian 'mined' by hand takes 250 seconds per block to break (assuming the player is standing on a solid block, dry, and has no relevant status affects), but does not drop an item.]
According to the Wiki it takes 250 seconds or 4 min 10 sec to break obsidian by hand.
(Technically that's not mining since the block is destroyed with no drops.)
Breaking blocks underwater takes 5 times as long, or 25 times as long if you aren't standing on the bottom.
So, 1250 seconds or 20 min 50 sec
Normal Level III Mining Fatigue from an Elder Guardian slows block breaking by 99.73%, which if I'm doing the math right means it takes 370 times as long (370.370370370... to be exact).
So 462962 sec or 7716 min or 128 hr 36 min or 5 days 8 hr 36 min.
(And multiply that by 5 if you are swimming rather than standing on the bottom.)
Refer to the question, assuming the player can breath infinitely underwater.
Refer to
https://minecraft.gamepedia.com/Obsidian#Obtaining base for an unenchanted diamond pick [Obsidian 'mined' by hand takes 250 seconds per block to break (assuming the player is standing on a solid block, dry, and has no relevant status affects), but does not drop an item.]
https://minecraft.gamepedia.com/Water#Slower_mining_speed (includes the effects of Aqua Affinity)
https://minecraft.gamepedia.com/Breaking#Speed which describes how to calculate the effects of various levels of Efficiency, Haste, and Mining Fatigue.
According to the Wiki it takes 250 seconds or 4 min 10 sec to break obsidian by hand.
(Technically that's not mining since the block is destroyed with no drops.)
Breaking blocks underwater takes 5 times as long, or 25 times as long if you aren't standing on the bottom.
So, 1250 seconds or 20 min 50 sec
Normal Level III Mining Fatigue from an Elder Guardian slows block breaking by 99.73%, which if I'm doing the math right means it takes 370 times as long (370.370370370... to be exact).
So 462962 sec or 7716 min or 128 hr 36 min or 5 days 8 hr 36 min.
(And multiply that by 5 if you are swimming rather than standing on the bottom.)
Just testing.
Oh boy!
a obsidian mined by hand takes about 34 minutes!
with fatigue it takes double longer! 68 minutes!
and underwated is impossible! it would take forever and i mean that by mentioning that it would be mined with the speed the bedrock will be mined!
check for more well-done math in AntVenom's video!
- Elon Musk