Nitrox compressors onboard?

[kenackr]

Hi all!

I'm a certified diver that is also Nitrox certified and will be going through the rest of the required training to be a qualified scuba instructor including nitrox instructor, gas blender and fill tech, etc. In the mean time, I'm in the process of purchasing a decent size sailboat that I intend to sail and dive the Caribbean with.

I have found that when I dive on Nitrox, I'm a lot less tired. Shortly after I purchase the vessel, a dive compressor of some sort will be installed on board so I don't have to run to shore for a fill. I'd like to be able fill tanks with nitrox as well as air.

To date, I have only found one company (Nuvair) that sells a small system with a nitrox membrane that is made for use aboard. That small system (complete with compressor) runs almost $10K (I got a quote) just for the equipment and shipping.

I'm not concerned about fill time since I have multiple tanks.

Does anyone know of a less expensive solution? Should I look into carrying a large O2 bottle that I can use for gas blending with fills from a small Bauer or Max Air, etc?

Appreciate any thoughts on the subject.

[Sunspot Baby]

Less expensive solution = air. If your on the boat you can get all the diving you can eat on air. No need for banks of mixing gases. Sometime low-tech is best tech.

Consider the weight of all those multiple tanks. Uses up ability to carry fuel, water, and beer.

George

[Ram]

Hi Ken
I owned & Operated a dive boat business part time for about 10 years, still have the dive boat & A very nice Bauer Compressor with only 25 hours on it.

I think you will find that Air is simpler, cheaper and more practical then Nitrox on board. I did over a 100 trips in the Bahamas from Palm Beach with divers onboard, and it becomes clear fast that nitrox is not needed, because you have much more time. ON my dive boat most people would not dive more than 2-3 dives a day, and in-between dive I would put them on shallow reefs to off gas, before you know it the whole day is gone.
I got out of the business, (libility)and would like to sell the compressor $3800 new I would let it go for $2500 if it’s something you might like.
Ram

[GordMay]

This investigation does not support the notion that reduced fatigue is an advantage of nitrox diving:
Nitrox breathing during a simulated dive did not reduce post

However, if your commited to nitrox - see Brownie’s NitroxMaker:
NitroxMaker Systems

[2divers]

But personal experience does... My wife was the one that pointed out after a weekend of teaching dive classes on Nitrox I was not nearly as tired as after a weekend teaching on air.

But, living on a boat, one has a greater amount of time to relax and enjoy. This means a lot less time hopping up and down to get things accomplished in a speedy, super efficent manner = more enjoyment and not nearly as tired.

2divers

[hellosailor]

Ken, I think you will find that any compressor on board is expensive, and the smaller they are, the more expensive the consumables that must be replaced (i.e. dessicant & filters).

Nitrox is after all just a FUD buzzword for "oxygen enriched air", which is a plain term but I think someone else decided to trademark that one as well?<G> So an oxygen bottle might be cheaper than the added nitrogen extraction equipment. You might think about diving on plain air and just using added O2 when/as needed.

Also note that you may be feeling some fatigue from the cold, even in warm water your body is burning away calories to fight it. "Enough" wetsuit to keep you warm may make a difference there.

To me, an O2 enriched mix makes sense but the term "Nitrox" just says "Money making scheme to sell certifications and bump up fill & VIP prices". Like PADI, selling extra classes to use a hand spear, camera, flashlight, colored fins, whatever.<G>

Sorry, but the way the old frogman trained us (and he was a gen-you-whine WW2 Navy Frogman) was to dive our tables, and if the mix just needs different tables, everything else falls under marketing and FUD. Like, hide the real breathing mix and sell it under a trademark name. (Not to ignore the other O2 issues, but they really *are* trivial and fall under simple good maintenance practices.)

[kenackr]

Guy's,

I have a really embarrasing story about me diving on air. I was going out with a really good looking woman who was also a diver.

We planned a week away in the keys it was to be our first time diving together. We were diving 3 tanks a day usually and having a lot of fun with the diving. By the time evening rolled around, I was usually out cold before 8 pm.

The short version is there was no hokey pokey at all that week, and she began to wonder out loud if I was getting ready to dump her. It took her almost 2 months to get over it once we got home and I recharged my batteries.

That experience never reapeated itself after I got certified on nitrox, thank god. I'll still dive air, but for me it's almost joining the preist hood!

At any rate, I really do feel the difference.

Ken

[kenackr]

Gord,

Really appreciate the tip on Brownies nitrox maker. I guess since the girl scouts had cookies all tied up, the brownies had to come up with something altogether different!

Ken

[kenackr]

Gord,

I checked into Brownies nitrox makers. Called the factory. The smallest nitrox maker they currently make runs about $49k US which fills 4 bottles at once and is made more for commercial service. They also extimated a smaller system might be had for $25k or so.

Ken

[Sunspot Baby]

Live aboard diving is defined by the 5 D's. Dive, Dine, Doze, Drink, Diddle.

If you're too tired to diddle at night, you either over participated in the drink or missed the afternoon doze. ;-)

I have said that diving is better than sex. I can do it 5 times in a day and still want to do it again (and that's on air).

George

[GordMay]

$25K sounds like a great investment - less than 3-year payback, if:
- you dive 3 times a week
- save a 1 hour nap per dive
and
- your waking time is worth $60/Hr

[kenackr]

George,

It must be the dozing thing, cause I don't know diddly about it and have never done it!

[Rick]

For the last few years I have kept returning to 32-36% nitrox because I discovered that when working underwater I don't "overbreathe" my regulator with Nitrox and I do earlier with air only.

When I dive tropical water I don't "work" per-se and never overbreathe my regulator on air and feel fine. I discovered the reason.

Just two months ago I went to a newly "graduated" allergist who tested me on a breath analyzer for asthma. She discovered that I had lost a significant amount of small air passageways (don't recall the medical term) and treated me for it. Much of it has been recovered and now I don't suffer the same effects as before.

It has long been known that emphasema and asthma patients ARE able to perform better on enriched oxygen. So I question the general results of the test that Gord referenced. Could be that it is valid only for people with "normal" lungs?

Comments?

[GordMay]

Originally Posted by Rick

”... Could be that it is valid only for people with "normal" lungs?”

The study does not purport to offer any definitive conclusions, and admits that “Practical impact unknown from this abstract.”
The study was a Double-blinded, concealed, randomised test of two sets of 12 recreational SCUBA diver volunteers*, performing 18 metre simulated** dives.
Findings: "This investigation does not support the notion that reduced fatigue is an advantage of nitrox diving."
Of course, absence of evidence is not evidence of absence.
* Probably “normal” subjects.
** Results may not extrapolate to 'wet' diving.

[hellosailor]

Gord, I noticed one large barn door open in the simulation study. You know, the kind that needs to be closed before good science leaks out of the barn?

Other than the tropics, most recreational diving is still wetsuit diving which, by the USN definition, also makes it cold water diving. We know that water pulls 14x more heat out of the body than air in a nice chamber simulation does, and when water pulls out heat, the body has to make more of it--which means oxygen use and metabolism and muscle efforts are all different.

Unless that study was done with the participants sitting in a nice cold jacuzza the whole time...I'd be inclined to call it bad science. It is "running the engine" (the human body) in an environment that is simply not the same as the one nitrox is often used in.

Might be valid for warm water divers--but unless that water is warm enough for you to stay in it for, say, four hours without feeling chilled?

Uh-uh.

Apples and oranges, just not comparable.