This made me rather sad

[cloudflint]

I just read this letter to the editor in diver magazine:

Some years ago I read a test in diver magazine about the Aqualung Mistral twin-hose regulator. This seemed to be the sexiest piece of kit I ever had seen and reading the promotional information quite an attractive proposition.

I don't remember the conclusion from your test at that time but a year or so ago having squirrelled away some funds I bought one from a UK dealer. I tried the unit in a pool to about 3 meters and was not particularly impressed with its performance but assumed it might perform better in dive conditions.

Later that year I tried it in Thailand, descending to a wreck at 26m. At this depth the unit could be made to deliver air only by swimming with the mouthpiece orientated to the left, and in fact I was forced to ascend to 20m to get sufficient air. The whole dive was a struggle to breathe, and i was very thankful to exit the water safely.

I had no other regulator so i did try one more time to use it. My second dive was to only 6m, and even at this depth the performance was abysmal, with frequent changes of orientation and depth to get air.

These units are in my opinion dangerous even in expert hands, and I am amazed that they have been sold without any indication that they routinely cease to function efficiently. I did contact apex, which told me (according to its French colleagues) that this was the sort of performance it would expect from a true demand regulator. It pointed to the section in the instructions regarding orientation of the diver vs the first stage as an excuse for the fact that this unit simply stops working under certain conditions.

I discussed the unit with an engineer who works on twin hose regulators. His opinion was that the diaphragm of the mistral was too small to be used as a twin hose set-up, comparing it with the diameter of some of the classic twin hose regs in his possession.

Apex offered me an entry level regulator as a substitute. I declined because i had paid more than £400 for the mistral, and an ATX40 offered was worth a fraction of that cost.

I still find the unit attractive to look at, but I wanted more than a piece of memorabilia. And i couldn't sell it to anyone knowing that it could find its way in tot he hands of a novice diver. If you are offered one of these units , either new or second hand, Avoid it like the plague. I am happy to say that Apeks/Aqualung withdrew the mistral from its product offering last year.

It makes me rather sad seeing DH regulators getting such bad press, especially since I read that letter having just come back from a 30m dive on my own new mistral where it breathed beautifully It sounds like a classic case of the second stage being placed to high on the back leading to bad performance and him having to tilt left to get a decent breath.

[Drado]

Can the author be tracked and directed to this site?

Did the editor of the dive magazine comment on the letter?

It is indeed sad that DHs receive bad press. I remember a conversation with an instructor I knew who told me that breathing through one was like sucking a golf-ball through a garden hose. I doubt he'd say that if he tried breathing with the bunch of tuned regs that this group owns. Sentiments like that are to me a double edged thing. Sure, it means that there'll be more DHs for the rest of us, but I personally woold like to see more people try one at least before passing final judgement. I remember one poolside conversation with another instructor who was amazed at how easy it was to draw a breath from my DH. If only more people could just try.

[Bryan]

My OPINION....If the new mistral was the only double hose ever made I would dive a single hose. Yes I have one....and I have done extensive experiments with it. Best part about the regulator is it's mushroom exhaust valve. The only double hose regulators that perform worse than it does are Triests and Dial a Deaths...Once again this is only my opinion. When you start by combining parts from a single hose with rebreather parts and then a tiny main diaphragm you are on a road to FAIL.....The small main diaphragm is the achilles heel of the Trieste....Why would anyone repeat that mistake expecting a different outcome?
Get it low down on your back, get some hose weights and have fun diving it. My wife uses the one I have because you can put a small single hose mouthpiece on it and she finds it more comfortable....BTW, she has never used a single hose regulator.

The lab that tests regulators for the Navy tested a new mistral, Phoenix and Broxton at various depths, work of inhale, exhale etc etc....Let's just say Aqua-Lung's marketing department would not be too keen on using the results for advertising...

If you enjoy diving it more power to ya! I hope everyone finds a regulator they are happy with and have many years of problem free service. Once again...My OPINION only.

[cloudflint]

Yeah the editor didn't respond but there was a response from Apex/Aqualung(i didn't include it initially since my little fingers where sore from typing ):

Landon Helsby, Apex Marine Equipment managing director, comments: when the regulator in question was brought to our attention we immediately offered to have it come to apex for inspection. The customer refused this offer, stating that he doubted that the regulator was defective, but just feels the Mistral is a dangerous product.

Without being able to test the regulator, it is impossible for us to say if it is faulty or not, but this is the only report we have had of this nature.

There are two important facts:

1. A twin hose regulator such as the mistral will not breathe as well in certain positions because of the location of the diaphragm from the mouthpiece, but this is mentioned in the literature.
2. the mistral has been tested and accredited to EN250, the european breathing performance standard for SCUBA, meaning the design is safe to use to 50m

Although the customer didn't want to send the regulator for inspection, we offered him an apex regulator in exchange as a goodwill gesture, but this was also refused. Although the mistral was not sold by Apex, but by the previous distributor, all offers we have made to the customer will stand.

If you enjoy diving it more power to ya! I hope everyone finds a regulator they are happy with and have many years of problem free service. Once again...My OPINION only.

To true, if someone dosent like a particular reg that dosent affect my enjoyment of it at all, im just kinda sad that now everyone has been saying to me "I read in diver magazine that ALL DH regs are rubbish" and some people who may have been interested in trying DH diving may read it and decide not to bother based on this report. But oh well at least i know i can always come here and find people who share my enjoyment

Dial a Deaths

haha ive never heard that expression before ill have to remember it.