# How long would it take to climb out of the Mariana Trench?

Assume for the purposes of this question that you can breathe underwater and can’t swim-in other words, it’s just like a mountain. How long would it take to get to the ocean floor from the deepest part, or at least to a point where you had to start swimming?

resist the urge to say “20 minutes”, resist the urge to say “20 minutes”, resist the urge to say “20 minutes” …

It might help if we had a number as to how deep that is. We know the Trench is deeper than Everest, but that’s counting from sea level, and you seem to be asking something different.

Why climb or swim? You can just float to the surface.

Not just depth but slope. Kilimanjaro is a tall mountain, but it’s a walking tour that most outdoorsy people can do. A standard tour is 5-6 days. Most of the mountains in the Himalayas are far more rugged. If the trench walls were like cliffs, it would take even longer. Conversely, a low slope might be easier but would add many miles of distance. I don’t know how the two factors would cancel.

If my google skills haven’t failed me, the deepest part of the Mariana Trench (Challenger Deep) is about 36,000 feet (numbers from google vary but they are all around there). The ocean floor in the Pacific is fairly uniform at around 14,100 feet.

If you want to climb to the ocean floor, you’ve got a climb of about 22,000 feet.

I don’t know how long it would take to climb that far.

After poking around some more on google, it seems that a climb up Everest can take anywhere from just a couple of days to close to two weeks, depending on the weather. One site said that the average is around 5 or 6 days.

I also googled for mountains that were 22,000 feet in height and found Nanga Parbot, which is the 9th highest mountain in the world. I found one expedition to there that had taken 5 days to climb the mountain and 2 to get back down.

So I’m guessing that if you assume your trench climb is like a mountain, it would take about 5 days.

You would have to calculate based on the actual ascent. Nanga Parbat’s summit is 26,660 ft above sea level, but the actual ascent from a base camp looks like it would range from 15,000 to 22,000 ft, depending on which route you took. However, an estimate of 5 days to a week might be reasonable for trained mountaineers.

Somewhat correlated question from a couple of years ago on what it would look like from the bottom of Challenger Deep.

from hiking 6000 ft per day would be a good upper limit for very fit hikers. This assumes a well marked and maintained trail

How steep are the walls of the Trench? The charts I see give the impression of a dramatic canyon with vertical walls, but they could be misleading.

That is more or less what i was asking, but I didn’t word it very well. I would love to see down there, but I’m sure it would freak me out, too.

From what it seems, not very steep. The trench averages 43 miles wide on average, and the trench maybe two-three miles deeper than the abyssal plain. That seems pretty gradual. Whether or not Challenger Deep specifically has steeper walls does not seem to be so certain, but for most of the trek, it would seem to be a leisurely hike.

Here’s a cross-section (note the vertical scale is greatly exaggerated). The slope on the eastern side is much less steep than on the western.