Taking decompression planning personally

A successful decompression schedule is the key to successful (technical) diving, but too often that schedule relies on hypothetical guidelines. The O’Dive is here to change that and help you take decompression personally. Here’s how.

*First of all, a disclaimer: this blog post is to introduce you to this concept. It cannot provide exhaustive information. The blog is based on having completed instructor training and having used it for a few months. If you want to know more, get in touch to sign up for a Zoom class.*

What is the O’Dive and how does it work?

There is a physical and a software part to this little machine. Physically, the O’Dive is a small Doppler ultrasound sensor capable of measuring post-dive bubbles in your bloodstream. This O’Dive app complements it. The app helps you record bubbles and allows you to upload your dive profile. There is also space for recording information like exertion level, how you felt on / after the dive etc. 

Divers send all of this information to a server in France, where O’Dive manufacturer Azoth Systems evaluates it. The automated evaluation is double-checked by Azoth’s scientists if there is any doubt about the result. If  you’re into technology, it’s a combination of artificial intelligence with good old human analysis. 

A personalised decompression rating

The result of the analysis is a rating of your dive and decompression profile in a Quality Index (QI) on a scale of 0 to 100. 

This rating is based on the bubbles measured within your body and an assessment of the dive’s ‘severity’. Put simply, severity is based on depth, length of bottom time compared to decompression profile and the length of decompression. Gases used also come into it. 

The personal decompression element

Measuring the bubbles in your body as accurately as possible is the key to receiving useful results. Not to be flippant, but if you have dived with me, you have most likely heard me say that diving is s sport for lazy people, with technical diving being a sport for lazy, efficient people. I mean that, and it applies here also. 

Placing the sensor correctly under you clavicle is important, and so is being relaxed when measuring. You see, lazy but efficient.

Bubbles are recorded in sets of left and right measurements taken at specific times after the dive. Ideally, divers take two sets of measurements, before sending them off for analysis.

So, what do you get back?

A few minutes after submitting information, results are sent back to the app. Here is what they look like: there is an overall rating of the quality of the dive first of all. 

Looking at the details, you can see where points were lost – on the severity of the dive or on bubbles.

Then, you can run simulations to see how your dives could have been improved. Of course, these are predictions. The idea is to give you guidance how you – personally – could make your decompression safer. It’s then up to you to try this in reality. 

Is it worth it?

Yes. Before you start, no, there is no guarantee that you will never have a decompression accident. 

However, this is a way of measuring how your own body reacts to the kind of diving you are doing. That’s the first time that this is available to ‘consumer divers’ on such an on-demand basis. So far, measurements like this have been reserved for scientists using more complex equipment. 

Of course, there are limitations. Measuring one dive will give you one data point; measuring several dives will start giving you a picture.

What have we discovered?

Reassuringly, the gradient factors we have been using so far have been proven to be ok based on the measurements taken over the last two months. However, the O’Dive has shown room for improvement. What I mean by that mostly, is a greater variation depending on the planned dive. 

At this stage, we would suggest distinctions between no-stop profiles, foundation-level decompression dives and deeper, longer dives. 

No-stop profiles are typical for the initial dives of many of our TDI courses as we get used to new configurations and practice skills. Here, it is very interesting to observe the difference in bubble formation between first dives and repetitive dives – liveaboard diving fans, take note!

‘Foundation-level decompression dives’ refers to the dives completed at the end of courses TDI Advanced Nitrox and Deco Procedures. This also includes technical experience dives at the 40-60 m level. At the risk of generalising, these dives are usually around the one-hour mark or a little bit longer with a bottom time of 20 to 25 minutes. 

Then there are deeper, longer CCR diving profiles. Based on the information gathered by ourselves and the divers who have been with us over those past few months, we’re now suggesting more tailored gradient factors than we previously did.

Another interesting observation (although we don’t have much data on this as yet) might be the difference made by using denser versus lighter gases. To be continued… 

What’s in it for you?

Right now, raise your hand (actually, drop us a message) if you’re interested in joining a Zoom session on this subject to find out more.

Once travel opens up, when you join us you will have a chance to use the O’Dive after your dives. This means, you have a chance to personalise your own decompression planning. 

One last thought

Just like knowledge and research about decompression continues to develop, so does the O’Dive. Whilst the algorithm that governs the results is based on well over one million dives, more information is added continuously. Much depends on the accuracy of the measurement, but the app helps with that and rejects measurements that are not up to scratch. 

All things considered, the ability to measure individual bubbles and get direct, personalised feedback is a benefit to all divers. It will not take away from individual divers’ responsibility to look after their health, plan their dives conservatively etc. But it does add a huger element of personalised decompression planning – and that is worth it.