On Mon, Oct 17, 2016 at 02:09:57AM -0400, Richard Aiken wrote:
> I discovered that a low sea level temp helps *tremendously.* Assuming a
> "sea level" atmospheric pressure of 0.01 and a desired atmospheric pressure
> of 0.90 atmospheres . . .
>
> A temp of 0 C requires 146,000 meters (`91 miles) deep.

40 km (25 mi) depth should suffice for that.  The calculator is
probably using an approximation that works well for aeronautics, but
fails very badly when applied to conditions outside its assumptions.

However, it is true that low temperatures reduce the required depths
for a given ratio of pressure.

- Tim