I want to murder my computer and feed it to the fishies!

[Hatul]

Thanks Adam

I looked into the simulator mode on my computer some more. (It doesn't work on desktop software). I was able to simulate a deco dive. Couple things I found

Skipping a deep stop does not increase deco obligation (That is if it is even allowing me to skip it, pressing the button to ascend as quickly as possible but how long it was at the depth is hard to figure out)

There is no warning on upcoming deep stops

Deco obligation still adds up even while ascending until it reaches approx 50 feet. - Yes even if it is done faster then 33ft/min. (ie the little bar on the side comes on, too many bars and it is uncontrolled ascent). Also, scanning the profile of the actual dive in question, it looks like I wasn't going extremely slow. The first bar showed on approx every second point so to me that seems that on average I was going up right around the rate it wanted, so as to not show a fast ascent. Interesting since using V-planner for the same depth, it shows that offgassing starts at approx 90 feet.


If it goes to a stop at 20 feet, I can no longer see how much I will have to do after at 10 feet. However I am able to see how many minutes it has planned to ascend so a little simple math and I get the gist of it.

Deco at 10 feet still does not count down reliably. Ie 12 minutes to clear 10, 25 mins to clear 22. No matter what profile I fooled with it always took longer. Considering that time cleared almost as well at 20 feet why am I trying so hard to be at 10?


You are right. But the things with overhead is that it really is simple. If I do it wrong I can kill or seriously injure myself.

Every single one of my dives here have an overhead environment. The purpose of the dive in question was to explore what my computer does in real world situations.


Thanks for all the help

I wonder if the clearing of the 10 foot deco time has to do with the computer adding a safety stop to the deco time? In my Vyper the Ascent Time in deco mode includes time to ascend to the ceiling (at 33 ft/min) + time at ceiling+ a 3 minute safety stop + time to reach the surface from the safety stop. What you're seeing as the deco time may include all those times, with the largest addition being the 3 minute safety stop.

According to my Suunto manual (which is probably the same for Mares) they recommend doing the 10 foot deco deeper than 13 feet to make sure the waves do not lift you above the 10 foot ceiling. Remember the deco depths are ceiling depths, that you're not allowed to go above. It's OK and desirable to stay below because you're still decompressing, just a little slower. Another explanation for increasing deco at 10 feet is that you went above the 10 foot ceiling and the computer penalized you.

As far as the ascent rate, it may be that your computer if it goes into deco mode expects you to ascend faster than 30 ft min in the deep part of the dive until you start to offgass (the floor).

I wonder why the technical computers don't include a safety stop? It may be that after doing a long deco the extra 3 minutes makes little difference or that the deco times already have that safety margin built into them.

Adam

 

[Hatul]

A good book that teaches how to calculate how much gas you need on a planned dive so you don't run out is

The Six Skills and Other Discussions ... by Steve Lewis. He's a good guy who reveals the technical "secrets". He'll even autograph the book for you.

Also useful for working out the size of pony tank to make it to the surface.

http://www.techdivertraining.org/OrderBook.html

Adam

 

[DuboisP]

I wonder why the technical computers don't include a safety stop? It may be that after doing a long deco the extra 3 minutes makes little difference or that the deco times already have that safety margin built into them.

the good technical diver knows a lot about deco and doesn't need to have a safety stop on his computer.
he planned his dive with security and can decide later if he will add or not some minutes of deco, depending the dive.

if you take the 2 following plans, you see 17 min deco more in the 2nd, for the same dive, by modifying the conservatism (security).
the 2nd is yet secure, so, adding 3 minutes....

VPlanner VPM B + 0
out at 140 min

VPlanner VPM B + 4
out at 157 min

 

[ianr33]

I wonder why the technical computers don't include a safety stop? It may be that after doing a long deco the extra 3 minutes makes little difference or that the deco times already have that safety margin built into them.

Adam

I think you might be onto something there.

 

[melanie.]

I wonder if the clearing of the 10 foot deco time has to do with the computer adding a safety stop to the deco time? In my Vyper the Ascent Time in deco mode includes time to ascend to the ceiling (at 33 ft/min) + time at ceiling+ a 3 minute safety stop + time to reach the surface from the safety stop. What you're seeing as the deco time may include all those times, with the largest addition being the 3 minute safety stop.

I don't know, because with the Mares as soon as the deco obligation is done it starts counting down a 3 minute safety stop. Did another simulation, and the time to ascend does not include a safety stop. ie I had 6 mins of deco, and it said time to ascend was 7 minutes.
As well, time to ascend while in safety stop is nothing.. so I am assuming that means 0

 

[ianr33]

Maybe the safety stop time is only included if it's an obligatory safety stop as opposed to an optional safety stop?

 

[Cave Diver]

Deco at 10 feet still does not count down reliably. Ie 12 minutes to clear 10, 25 mins to clear 22. No matter what profile I fooled with it always took longer.

It's likely including time for a safety stop, even though you've completed deco stops. I've had a computer that did that.

 

[Cave Diver]

Did another simulation, and the time to ascend does not include a safety stop. ie I had 6 mins of deco, and it said time to ascend was 7 minutes.

If you had 6 minutes of deco, say at 10', that 7th minute is probably time to surface. i.e. you should take one minute moving from your 10' stop to the surface.

 

[melanie.]

I thought all safety stops by definition are optional?

Either way, if it wanted me to do more time, why would it not just add more minutes to my obligated time? Trying to "hide" it in there just seems pretty useless and inconvenient to me.

 

[melanie.]

If you had 6 minutes of deco, say at 10', that 7th minute is probably time to surface. i.e. you should take one minute moving from your 10' stop to the surface.

Well yeah lol.
Interesting though that when I am at the same depth and its counting down safety stop it doesn't give me a minute to ascend.