Questioning the need for altitude adjustments

[boulderjohn]

First of all, I understand how to adjust for depth at altitude, and I have seen various tables for this. That is not the question I am going to ask.

I have been surprised lately to learn that not everyone believes that altitude adjustments are necessary, even when doing fairly aggressive decompression dives. For example, UTD as an agency does not believe altitude needs to be considered in dive planning.

I am curious about how others feel about this.

 

[Walter]

Why does UTD not believe altitude needs to be considered in dive planning?

 

[fdog]

I compensate for altitude.

For our typical profiles, compensating for altitude is about 7-10 minutes more run time than it would be at sea level.

Doing this hasn't got us even a niggle. Haven't tried running a sea level profile - I'm a scardy-cat I guess.


All the best, James

 

[boulderjohn]

Why does UTD not believe altitude needs to be considered in dive planning?

Unfortunately, a computer crash cost me the exact wording because I lost the email, but Andrew's experience with diving the same profiles at different altitudes tells him it doesn't matter.

I hesitate to say more because I would be speaking for someone other than myself, and that is always dangerous.

 

[gcbryan]

It's hard to comment on something that we can read first.

Edit: I just checked the UTD website and this question was asked but only briefly addressed. The answer was that Ratio Deco takes this into account along with the usual flippant answer which was that "we don't do our deco on the surface".

Without a better answer than that I can only assume that there is enough padding in Ration Deco to compensate for the rather smaller difference that altitude makes in general.

Otherwise, I think we need more facts from the source.