Mandatory safety stop vs. deco

Dirk Hohndel dirk at
Mon Sep 9 08:11:16 UTC 2013

On Mon, 2013-09-09 at 18:07 +0300, Miika Turkia wrote:
> I have one dive that according to libdivecomputer/subsurface goes into
> deco. However, the dive was actually a non-deco dive with a bit of
> extra excitement caused by heavy up current (roughly from 13 to 8
> meters in 10 seconds). Due to the rapid ascent, Suunto gave a
> mandatory safety stop that is currently considered as going into deco.

That's almost a philosophical question...

If a safety stop is "mandatory", how is it different from a "deco stop"?

> I want to throw in a question whether this should be considered deco
> or not. I guess one can argue either way but nevertheless it was a
> surprise to see the deco marking in subsurface.
> libdivecomputer/src/suunto_d9_parser.c:
> case 0x01: // Mandatory Safety Stop - odd concept; model as deco stop
>        sample.event.type = SAMPLE_EVENT_SAFETYSTOP_MANDATORY;
>        if (type & 0x80)
>               in_deco &= ~DECOSTOP;
>        else
>               in_deco |= DECOSTOP;
>        break;

So yes - this was a conscious decision that I made when implementing
this. If people feel strongly about it, it's of course open to
discussion, but as I mentioned above, I find this a subtle distinction
without a difference...


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