Teaching Dive Tables (including Nitrox)

[Belzelbub]

So tables are wrong, computers are wrong. How do YOU actually control your dive?

I know this wasn't directed at me.

Yes, computers and tables are wrong if you think they are calculating what is actually going on with the tissues in your body. That is essentially the point of Shearwater's Critical (Red) Warning. It's a guess. Based on science, so it's an educated guess. Still a guess.

The tables and computer are tools that the diver can use, but the diver should also take into account how they are feeling before, during, and after the dive. They should absolutely make decisions on all the data. Just because the computer says the dive is OK doesn't mean it's a guarantee.

The Dive Readiness feature that Garmin added to the MK3 line is a step in this direction. Apart from factors related to previous dives, it doesn't appear that this affects the calculations in any way, but it's additional information for the diver. It uses fitness, sleep, etc. to give a number between 1 and 100 to indicate potential physiological readiness for a dive. Again, it's just a tool, but this is a step toward actually taking recent history into account.

 

[DiveLikeAMuppet]

I know this wasn't directed at me.

Yes, computers and tables are wrong if you think they are calculating what is actually going on with the tissues in your body. That is essentially the point of Shearwater's Critical (Red) Warning. It's a guess. Based on science, so it's an educated guess. Still a guess.

The tables and computer are tools that the diver can use, but the diver should also take into account how they are feeling before, during, and after the dive. They should absolutely make decisions on all the data. Just because the computer says the dive is OK doesn't mean it's a guarantee.

I, like many people, obviously adjust my deco based on how I feel, whether I was working hard on the bottom or cold during the stops and whether my loop felt stable at the last stop. I also take into account surface conditions and what boat pickup might look like and if anyone will help with stages. That wasn’t the point. The point was that OP keeps saying what’s wrong but doesn’t propose how to do things right.

 

[Patrick B Manning]

I'm an SSI OWSI and I only show how to use them as a "familiarization" when discussing dive computers and dive planning. That is to say, I show them how to figure a multi-dive plan using tables, then immediately show them how to understand the exact same dive profile using a computers and how they are better in every way. LOL!

I’m an SSI AOWI and I teach every student for OW how to use the tables, where to find them and why until they have a dive computer why they have to dive more conservatively using the tables. I then give a retracting for Nitrox before showing it with the computer. Same with deep diving specialty. It’s also easier to get them to seek out using a dive computer, whether it be renting or buying, once they see the work involved using tables.