• A decompression computer is not a substitute for planning your dive and carrying decompression tables. Plan your dive, dive your plan and carry backups tables.
• I paid full price for my Liquivision X1 (bought it used off a bloke in Canada) but I will be getting a Liquivision X-link for 50% of the list price because I am working on a 2 pager about using the X-link with a Dive Rite O2ptima for Liquivision.
• My experience is with the X1 is only with the V-Planner Live software installed. This post relates to this particular configuration unless otherwise noted.

Experience

When I bought my rebreather, I already had a Delta-P VR3. In addition to that deco computer (which I bought the Trimix and Rebreather/PPO2 software pins for) my O2ptima comes with a Hammerhead primary handset that’s deco-enabled (Buhlman GF). Having just spent so much money on diving equipment I wasn’t looking to buy a new deco computer.

Six months later, my dive buddy Sam bought a Megalodon Copis rebreather. Since the basic Copis doesn’t come with a deco capable computer (really just a PPO2 display) he chose to buy the new Liquivision X1. At the time, not much was known about the X1 but he had seen me struggle with the VR3 and thought the user interface was awful. The idea of being able to chose which software to put on the X1 was attractive as was its user interface both in terms of tapping and screen display.

I actually didn’t think the X1 was a great choice for him at the time as the X-link wasn’t available (it still isn’t at the time of this writing but should ship mid-december 2008) so the X1 could only give him deco information based on a pre-set PPO2 as opposed to reading it real time the way my connected VR3 did. I thought this was especially true of a manual CCR like the Copis he bought. In any case, he loved his X1 and after diving a few times with him as my VR3 failed again and again I went ahead and bought a used (but never wet) X1.

As you may know by now, I dive an eCCR, a life support system which purported goal is to attempt to kill me when I won’t be watching. I was taught to watch though and that means monitor my PPO2 (Oxygen Partial Pressure) frequently. Like any O2ptima rebreather diver, I have a primary on my left wrist that I can check for PO2 as well as a heads up display (the HUD is driven by the secondary handset, which is tucked away in a belt pouch) both of which read from three same oxygen sensor. When I was told about the possibility to add a third computer to the lot which would monitor a fourth cell as well as give me a redundant source of deco information, I jumped on it.

I already owned a Delta-P VR3 which was compatible with this setup. As I was taking my Advanced Nitrox and Deco class years before, I had been co-erced into buying a deco-capable dive computer. The VR3 seemed wonderful with its expandability. And in truth it was.

The Delta-P VR3 is a beast of a dive computer, looking more adept at breaking a lobster shell around a beach fire than being attached on a human wrist. It feels and looks solid if somewhat antiquated. Its main selling point at the time is that you could upgrade it as needed going from Nitrox diving to Trimix, Open Circuit to CCR, Bullman to VPM. And that’s exactly what I did with it, ending up paying around $2000 for the whole getup.

I want to say that the VR3 served me well over the year but that wouldn’t really be true. On my first Open Circuit deco dive, on the deck of the German U-Boat U853, the brand new VR3 suddenly shut off, its screen displaying no information, therefore engraining into my brain that backup tables compulsory. The culprit was supposedly the AA battery I was using instead of a leaner but supposedly compatible european LR6. During the 10-15 hours of my CCR training, it performed beautifully but for the next 5 dives, it would shut off occasionally, complain about low battery or think it was underwater, missing stops, while I was driving to the dive site. It was a backup computer I had learnt to not count on which defeats the purpose. But then again, for 20 hours of CCR diving in the Bahamas, it worked without any issue.

You probably will ask why I never sent it back ? Well, it mostly worked … and the factory is back in the UK and charges quite a bit of money for an overhaul.

I think another reason though is that I knew it wouldn’t be my computer for long. You see, the main issue I have with the VR3 is that it probably has the worse user interface I have ever seen. I might not remember much from my MS-DOS days but it must have been conceived then. Most VR3 users will tell me they find it intuitive but I think they just got used to it. No one can pick up a VR3 and use it immediately. After a few weeks out of the water, I would often forget how to calibrate it, how to set the bailout gases, change the screen orientation. Simple operations such as turning gases on and off or setting them up take a long time and shouldn’t.

Blinded by the fact that I wanted my buddy Sam to use the same gear configuration I had, I even tried to convince him to buy a VR3. He wouldn’t have none of it and he was right. So he went and bought a Liquivision X1. More on that later.

Pros and Cons

Let’s look at the VR3, objectively:

• Solid piece of equipment
• Bulky, oddly shaped
• Deco Algorithms: Bulman or optionally VPM ($)
• _very_ conservative, ‘won’t get you bent’
• User interface is far from user friendly
• Can be purchased bare (Nitrox Open Circuit, Monochrome) then upgraded (Trimix, CCR, Color) as you need it
• External PPO2 (CCR), Wired High Pressure Sensor, O2 Analyser options
• Downloadable dive log option is expensive and software is antiquated at best
• Readability is decent but not outstanding. New HD screen doesn’t seem to be much of an improvment
• Batteries are end-user swappable but picky in real life
• Firmware is not user upgradable and requires sending back to the factory (and is not free)
• Can probably pick up a used one for cheap on ebay or one of the tech divers forums

Conclusion

Should you buy a VR3 today ? Probably not. While Delta-P recently released an updated model (the VR3 HD) the software isn’t much better and the screen readability hasn’t improved much. The VR3 was one of the best dive computers in the early 2000 but newer better computers have recently been introduced (Shearwater Pursuit and Liquivision X1 are fine examples). Delta P themselves have a new computer, the VRX with a new form factor and deco algorithm. So if you’re in the market for something great, pass on the VR3. But if you’re on a tight budget, don’t mind buying a used computer, the VR3 is a solid decompression computer.

Why did I bother reviewing the VR3 you may ask ? Even though it’s becoming the grandfather of modern day deco computers, the VR3 is relevant. It’s a yardstick if you will, something new computers will be judged against because there are tens of thousands of old VR3s out there. And with the Liquivision X1, Shearwater Pursuit and upcoming Dive Rite Nitek X, I for one am looking forward to trying them all out.

Next…

The Liquivision X1 deco computer and its PPO2 interface, the X-link

Disclaimer: A decompression computer is not a substitute for planning your dive and carrying decompression tables. Plan your dive, dive your plan and carry backups tables.