Petrel average depth calculation

[Zeekat]

A little data crunching:

PDC: average depth reported: 61'
Desktop: average depth reported: 59.3'
Xcel: (1) average function applied to all depth data: 59.344'
(2) average function omitting zero values at end: 60.475'
(3) average function omitting first value and zero values at end: 60.528'

Hi rhwestfall, I came to the same conclusion. In my opinion, there is an error in the desktop programme: In the settings menu of the DC, you can enter an "end of dive delay". After this delay on the surface, the DC will start a new dive. In the desktop programme however, this delay is taken into account when calculating avg depth. As this delay is per definition at 0m depth, you will get a shallower average from the desktop programme. The average, shown on the DC is the correct one (i.e. without the end of dive delay). Yesterday, I emailed Shearwater about this bug, and I'm waiting for their reaction... if any...

Michael

 

[Zeekat]

Hi rhwestfall, I came to the same conclusion. In my opinion, there is an error in the desktop programme: In the settings menu of the DC, you can enter an "end of dive delay". After this delay on the surface, the DC will start a new dive. In the desktop programme however, this delay is taken into account when calculating avg depth. As this delay is per definition at 0m depth, you will get a shallower average from the desktop programme. The average, shown on the DC is the correct one (i.e. without the end of dive delay). Yesterday, I emailed Shearwater about this bug, and I'm waiting for their reaction... if any...

Michael

Two days after my email to Shearwater, I already got an answer. They confirmed that there is indeed a bug in the desktop software, but that the average depth on the petrel is the correct one. They will correct this in the next software update.

I think that this is top service, and they showed that they are really concerned about their products and their customers!

 

[Stoo]

During a dive, if you run the Dive Planner in the Dive Setup menu, you will see a list of all future stops based on the current conditions.

I find that having a look at this is a great way to pass the time while hanging. It's bit like scrolling through the future turns on your GPS so you kinda know what's coming...

 

[JohnnyC]

I find that having a look at this is a great way to pass the time while hanging. It's bit like scrolling through the future turns on your GPS so you kinda know what's coming...

I like watching that and the tissue graph while hanging. I find it intriguing, even though it's a hypothetical, that I can see what's going on inside my body.