Diving the VR Technology NHeO dive computer

VR Technology, famously known for the VR3 multi-gas dive computer for open and closed circuit rebreathers offered the trimmed down version of the VR3 dive computer offered for only a short time; known as the NHeO, this short run computer was the predecessor of the NHeO3.

While not being exactly the poor man’s VR3, the NHeO was a compact version of the VR3 dive computer housed in a technopolmer case as opposed to the metal alloy case of the VR3. The NHeO along with the VRx is a very streamlined unit as compared to the sometimes described clunky VR3.

With my rapidly declining vision, I found the backlit screen easy to read underwater even with the slightly convex curved screen. The computer comes from the factory in multi-colour mode for the first three dives before reverting to mono screen, the colour PIN will activate the multi-colour screen, should you decide to upgrade.

Unfortunately, I never needed to upgrade to the colour version PIN as the computer did not perform the mandatory three dives.

The NHeO was capable of storing and utilising four different gasses during the dive as opposed to ten gasses supported by the VR3 and VRx computer; for many divers seeking to gear up for staged decompression diving, the NHeO and later NHeO3 version is a perfect computer that may be easily upgraded in the future without requiring replacement of the whole computer.

The NHeO was a full decompression computer utilising a Buhlmann ZHL-16 decompression algorithm incorporating deepwater stops. The user manual stated that should the deep micro-bubble stops be missed, a use tables message would appear and a decompression schedule will appear that is very close to the required stop duration. 

To my way of thinking, before undertaking any decompression stop dives, a full dive plan should be calculated with gas management, CNS tracking, a depth violation and a bottom time violation calculation carried on a slate as a backup to the plan, this is a prudent practice anyway. 

I never missed a deep stop on the NHeO but have done so on my VR3 at times when deep stops are difficult in a situation as a raging down current forcing excessive gas usage to maintain depth, the use tables message is a real pain.

The diver also has the option to switch gasses underwater and the computer calculates the new profile and while I have not done so far, I will be doing this in future dives. I am also planning on diving air profiles with nitrox mixes to violate the algorithm to view the in-water results.

Miss the deep stops and exceed the ascent rate, the user manual states the NHeO will not lock the diver out during a dive and I would like to know the extent the computer reacts to such diving practices.

On a recent series of dives with the Mares icon computer (before that dive computer failed); I unstrapped the computer from my wrist and raised the computer above the 3 metre decompression ceiling with my lift bag to see the effect on the profile.

While an audible alarm sounded, the computer showed no violations on the screen and did not penalise further dives that day, this somewhat concerned me.

While such practices are not recommended, I did not actually violate my planned stop depth, had a back-up computer calculating my ceiling and had back-up tables on a wrist slate. 

It is important to have sufficient trust in the computer you are using, hence the fact that I always select a Buhlmann based computer for decompression stop dives and I believe in the VR Technology product.

I was using my icon computer for standard non decompression dives and my technical computer for more advanced dives. Usually, I use my older Suunto Vyper computer set in gauge mode as a back-up depth and bottom timer but on this occasion the icon computer served as back-up computer on this overseas trip.

I do not have the luxury of having a pressure vessel to test a number of profiles or violations. Nor should I, after reading the user manual and strapping a computer on my wrist, I should be able to take a computer from the box and go diving. 

The two switches are located at the bottom of the computer and work by using a short push of either (one) switch, a push and long hold of one switch, a short push of both switches or a long push and hold of both switches.

This takes a little while to get used to and I practised extensively before leaping into the water with my brand new NHeO strapped to my wrist. As yet, I haven’t attempted to play around too much on my initial dives on the NHeO; I thought I would get a little bolder in the future.

The VR Technology NHeO was an ideal air/nitrox dive computer competitively priced and starting at $679, the N1 coded NHeO will get the diver an open circuit air/nitrox computer, when the diver’s experience warrants, an upgrade PIN will open the diver to trimix diving for under $200.

So for under $1000, a diver has a trimix capable computer manufactured by a proven performer built on the knowledge and experience of the VR3 and VRx dive computer platforms.

The Buhlmann ZHL-16 algorithm is a respected and time proven algorithm equipped with the latest micro-bubble avoidance deepwater stop profile.

My NHeO dive computer didn't last long; the computer failed and I immediately contacted VR Technology, they informed me they will immediately replace the computer with the new NHeO3 computer.

However, there would be a waiting time of a month as the new computer was rolled out. I informed them that I needed my computer right now so they ended up sending out a C4 VR3, thanks guys.