Dive planning with subsurface

[Linus Torvalds]

On Fri, Oct 11, 2013 at 1:31 PM, Tim Wootton <tim at tee-jay.demon.co.uk> wrote:
>
> I wouldn't say NOAA are especially conservative, for 35m PADI RDP gives only
> 14mins NDL, and for 33m BSAC88 gives just 13mins NDL.

.. and all dive tables tend to assume you do reasonable descent/ascent
rates. So if NOAA says "20 min at 34m", they don't mean "go down to
34m, stay there for 20min, you'll be ok". The 20 min is total dive
time. What Willem seems to describe is literally "stay at 34m for 20
minutes", which does *not* sound like a no-deco dive to me (and
subsurface obviously agrees).

For example, if you say that you'll take 3 minutes to go down to 34m,
then stay there for 10 minutes, take 3 minutes to ascend to your
safety stop, and do a three-minute safety stop, then the subsurface
dive planner seems to be perfectly fine with that kind of ~20-minute
dive (I didn't check the details - I'm diving imperial, and I just
noticed that the dive planner does it *graphically* right, but gives
insane numeric depth values in the side-bar).

               Linus