What computers are you using for tech dives?

[rongoodman]

Switching from 21/35 to EAN50 gives you an ICD hit. The Bühlmann is a simple algorithm and does not protect the diver from mistakes or suicidal attempts. The RGBM however, being a slightly more accurate model of what happens in the diver's body, reacts in more details to what the diver does. So in this dive the RGBM algorithm tries to protect the diver from being bent or killed by a suicidal counterdiffusion by prolonging the decompression.

I think you're going to need to provide some support for these assertions. "Suicidal counterdiffusion" from 21/35 to 50% would imply a lot of episodes of ICD from a very common combination(N2 is only increasing from 44% to 50% at the switch). Mitigation strategies for ICD usually involve decompression gas choices, not prolonging decompression times.

 

[kensuf]

Hi! I just jumped here following a link from another thread. I feel I have to comment on this although it is an old post. I did not see anyone else reacting on the ICD in this dive when I quickly browsed other following posts.

Switching from 21/35 to EAN50 gives you an ICD hit. The Bühlmann is a simple algorithm and does not protect the diver from mistakes or suicidal attempts. The RGBM however, being a slightly more accurate model of what happens in the diver's body, reacts in more details to what the diver does. So in this dive the RGBM algorithm tries to protect the diver from being bent or killed by a suicidal counterdiffusion by prolonging the decompression.

The P0 means nominal personal setting. One should set the personal setting to a higher value when diving in cold, when under fatigue, at old age, in bad physical condition, when inexperienced, long time since last dive or with minor medical issues. In good conditions the personal setting can be set more agressive (negative) to shorten the decompression. This is like tweaking the Bühlmann gradient factors according to personal conditions.

- Tom from Suunto

Hi Tom,

Can you give us one documented case of ICD that was caused by going from a normoxic trimix to 50% nitrox at 70' during decompression?

Just one.

Thanks,

Ken

 

[TrimixToo]

Hi! I just jumped here following a link from another thread. I feel I have to comment on this although it is an old post. I did not see anyone else reacting on the ICD in this dive when I quickly browsed other following posts.

Switching from 21/35 to EAN50 gives you an ICD hit. The Bühlmann is a simple algorithm and does not protect the diver from mistakes or suicidal attempts. The RGBM however, being a slightly more accurate model of what happens in the diver's body, reacts in more details to what the diver does. So in this dive the RGBM algorithm tries to protect the diver from being bent or killed by a suicidal counterdiffusion by prolonging the decompression.

<snip>

- Tom from Suunto

Please show us the exact profile you think would cause an ICD problem on a switch from 21/45 to EAN50. (Hint: Even at the MOD for 60 minutes, the PPN2 and PPHe, and the sum of the two PPs, are continuously decreasing on deco <edit> except for a tiny bump in PPN2 if you switch at 70' that you can avoid by switching at 60'.)

I'll add that 21/45 is a bit of an oddball mix for open circuit. Far too much O2 to go very deep, and more He than necessary at its MOD.

Edit: Clarify my "hint."

 

[LiteHedded]

Hi! I just jumped here following a link from another thread. I feel I have to comment on this although it is an old post. I did not see anyone else reacting on the ICD in this dive when I quickly browsed other following posts.

Switching from 21/35 to EAN50 gives you an ICD hit. The Bühlmann is a simple algorithm and does not protect the diver from mistakes or suicidal attempts. The RGBM however, being a slightly more accurate model of what happens in the diver's body, reacts in more details to what the diver does. So in this dive the RGBM algorithm tries to protect the diver from being bent or killed by a suicidal counterdiffusion by prolonging the decompression.

The P0 means nominal personal setting. One should set the personal setting to a higher value when diving in cold, when under fatigue, at old age, in bad physical condition, when inexperienced, long time since last dive or with minor medical issues. In good conditions the personal setting can be set more agressive (negative) to shorten the decompression. This is like tweaking the Bühlmann gradient factors according to personal conditions.

- Tom from Suunto

 

[PfcAJ]

Hi! I just jumped here following a link from another thread. I feel I have to comment on this although it is an old post. I did not see anyone else reacting on the ICD in this dive when I quickly browsed other following posts.

Switching from 21/35 to EAN50 gives you an ICD hit. The Bühlmann is a simple algorithm and does not protect the diver from mistakes or suicidal attempts. The RGBM however, being a slightly more accurate model of what happens in the diver's body, reacts in more details to what the diver does. So in this dive the RGBM algorithm tries to protect the diver from being bent or killed by a suicidal counterdiffusion by prolonging the decompression.

The P0 means nominal personal setting. One should set the personal setting to a higher value when diving in cold, when under fatigue, at old age, in bad physical condition, when inexperienced, long time since last dive or with minor medical issues. In good conditions the personal setting can be set more agressive (negative) to shorten the decompression. This is like tweaking the Bühlmann gradient factors according to personal conditions.

- Tom from Suunto

Are you REALLY a Suunto employee? This is representative of Suunto's knowledge of DCS and diving practices? This must be really embarrassing for your supervisor.

I'm not interested in using a Suunto dive computer in the slightest, and this solidifies my opinion. Absolute nonsense.

 

[victorzamora]

Hi Tom,

Can you give us one documented case of ICD that was caused by going from a normoxic trimix to 50% nitrox at 70' during decompression?

Just one.

Thanks,

Ken

Remember that it's not just an ICD "hit." It would have to be bad enough and consistent enough for Tom to call the practice "suicidal."

 

[kensuf]

Remember that it's not just an ICD "hit." It would have to be bad enough and consistent enough for Tom to call the practice "suicidal."

I can't even fathom how many normoxic trimix courses made such a suicidal gas switch. Wait..

 

[100days-a-year]

Found the conditions under which ICD became such a threat.
Going back to screenshot that post before it gets deleted to use as another reason not to recommend Suunto for anyone not an elderly overweight smoker and drinker with a PFO .

 

[victorzamora]

I can't even fathom how many normoxic trimix courses made such a suicidal gas switch. Wait..

I'd guess somewhere at least 95% of them.

 

[PfcAJ]

I can't even fathom how many normoxic trimix courses made such a suicidal gas switch. Wait..

Can confirm, am dead.