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Comment by meric | Hacker News Reader

If you're asking about the oxygen levels, I'd say so. At a rough guess of 1m^2 of oxygen per person in the boat, for two people. That's an hour of walking according to the article. (Assuming water takes less oxygen to walk in)

I think it'd float to the top though. It'll need some kind of weight...

A one ton metal boat shaped object would do:

http://kwc.org/mythbusters/2007/11/episode_92_pirates_2_row_...

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The first diving bells didn't have a system to refresh the air supply, they were still used for meaningful work.

https://en.wikipedia.org/wiki/Diving_bell

Nitpick: s/1m^2/1m^3

> I think it'd float to the top though. It'll need some kind of weight...

A simple way of thinking about it is that boats float because they contain air (rather than water). The fact that they are upside down or the right way up changes little.

Since the rowboat can support two people, it should definitely float to the surface, dragging them along with it.

> Since the rowboat can support two people, it should definitely float to the surface, dragging them along with it.

Only if the air bubble occupied the entire inner portion of the hull. If it were, say, only half the volume of the hull - I suspect it would be neutrally buoyant with the weight of two people.

People are roughly* neutrally bouyant in water. Thus they don't weigh anything when submerged. Otherwise swimming would be very hard indeed. So you would need to weigh down the boat to sink all that air and wood.

*depending on depth and body composition, but give or take a bit, neutral.

Agreed, but boats when not filled with air are typically negatively buoyant. I'd wager that there's an air bubble small enough to make the whole system negatively buoyant, but large enough to sustain the people breathing it for some period of time.

The CO2 buildup would kill them long before they reach the 17.5% O2 mark. And considering how hard it is to actually walk in water, i'd say it would almost be equivalent to working out. According to the article, a person that is heavily working out would have 10 minutes to reach the 17.5% mark in a 1m^3 area. So maybe 20 minutes for the boat people? And that is neglecting the CO2.

Except both oxygen and CO2 diffuse in and out of water so that buys you time, especially if the water current is constantly keeping the concentrations equalized near the boat.

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