Hydro Atlantic without Helium?

[Superlyte27]

And for those of you not paying attention, 10/65 in CCR is completely okay at the surface. For years (and because I was diving a P.O.S. rEvo) all I ever put in my CCR was 10/70 to make it breathe easier.

 

[JohnnyC]

Just out of curiosity, when would helium not be available?

Third world countries maybe? I was speaking globally in that regard, as the parameters described for diving the Hydro Atlantic also exist elsewhere. But specifically for the Hydro Atlantic, I don't see a reason to dive anything else....

 

[RyanT]

@JohnnyC, gotcha.

 

[Stoo]

FWIW, the deepest wreck "regularly" on most advanced diver's list here in Tobermory begins in 70' and bottoms out in 155'. She doesn't get interesting until about 125'-130'. I would say that the VAST majority of people diving that wreck are doing in on air. It's really only GUE divers that don't. Mind you, most folks are only spending a few minutes at that depth. On the other hand, the water temperature is generally around 40° at depth.

With only one shop in Tobermory these days, you can't even buy helium here, although a few folks in town may have a bottle in their shed and a Haskel. So I've heard anyway.

The Forest City

 

[Colliam7]

I want to dive the Hydro more since it is in my backyard. . . . How many of you guys and gals have done it on nitrox (22%-23%). . . . Let me know what you guys think or if you believe it is a helium only dive.

I do not believe it is a 'helium-only' dive, having dove it 4 times, on air as my backgas, to the sand each time. So, I have not dove it on enriched air, backgas, either. I don't know that I would consider a 22% mix to offer sufficient bottom time benefit to bother with it./ But, others may disagree.

There are good comments in the thread about the value of helium, and about the variables that can accent the narcosis (current, workload, etc.). I won't say I didn't experience narcosis on those dives, because I did. But, it was not problematic under the conditions I experienced on the days I dove it.

If there was no additional cost associated with helium, I - probably like most trimix divers - would routinely use it on dives below 130'. Some would use it on dives below 100'. But, because it does add to the cost, divers like the OP - and me - understandably think about when to use it.

 

[Germie]

It will always be a discussion and a personal opinion. In warm waters I don't need helium at 160 ft. I even don't have problems with diving to 200 ft on air in warm clear open water. It is quite normal here, with cmas 3* you are certified to dive to 60m/200 ft on air, and the French divecenters bring you to such deep wrecks and only fill air and nitrox. More accidents? No numbers are known. But I don't teach deep air, I have to dive air also and am responsible then. In my country it is almost impossible to go over 30m and there is no need to go deeper for a 3* cert (standards talk about 24m as max). But you sign a deep air cert off then, most instructors don't realise that as the regional cmas states 30m, it still is an international cert and then it is 60m (or nowadays PO2 of 1.4, so 57m). So in France this divers go for the first time so deep and there is no decompression theory in the 3*. Doing a 'shallow trimix course' is never bad, and I don't teach the cmas specialty decompression diving where you do a decodive on a single tank with air as backgas and no decogas. And it is always nice you can choose, helium or not, so that is why I advice people to do a trimixcourse even inf they want to stay in the adv. nitrox regions. Sometimes I prefer helium and sometimes there is no need to. On ccr it is easier to take helium in your mix. It is also a difference in cold dark water. Or in caves. But I don't like people who state you have to dive helium over 100 ft or over 130ft, it still is a personal choice. And nobody is same. The technical diver course I don't teach, then it will be normoxic trimix. I am responsible, and the divers are not experienced at such depths. So better to have myself a clear head I can react when needed. Same with students, some do the course, but are a little bit afraid of depth when they have to go for the first time deeper than they have ever been. And some divers already are narked at 40m. After, you can choose.If helium has same price as nitrox, I would do more oc trimixdives of course. But for short botomtimes and with such high prices of helium, yes, costs play a role.

 

[stretchthepenn]

Did you do it at the surface before to do it underwater ?

One would expect to be significantly faster the second time, you do a puzzle.

Yes to both. That's why I wrote, "[the instructor] timed me first on the surface and then at 100'.

Doing the test topside primed me for the underwater test."

 

[dave22387]

So the survey is split 50/50...

 

[JBlackman]

The important thing here is to know yourself and know the conditions. Are you susceptible to narcossis? What's your personal limit? What's your experience been diving similar conditions (temp, current, viz) at shallower depths?

If you really should be diving Helium mixes but the cost is prohibitive, you should stick to shallower dives. No one can decide for you if any given dive is a Trimix dive or not, although I understand why you'd ask.

 

[OceanEyes]

I do not think that helium should be REQUIRED as the OP asked, and this specific word caused me to reply “no” to the poll.

I’ve dived the Hydro several times on Nitrox, but the last time I did so was over 20 years ago. I gravitated to CCR and do not make that dive with air diluent.

Can you make this dive without helium? Of course you can.

Should you make this dive without helium? That’s your decision to make, and this thread has provided plenty of food for thought.

Can I make this dive without helium? Yes.

Will I dive it without helium? Not any more.