What solo cert do you have, has it ever been turned down?

[PBcatfish]

...In six boat dives this first week of diving I’ve witnessed two extremely concerning things.

One. New diver, uncontrolled ascent from 60 feet after 15 minutes down because of equipment dysfunction.

Two. 32% nitrox Diver planning a 127 foot dive. The MOD on that baby is 111 feet. Just saying. The dive op changed the dive at the last minute (we were on top of the dive) because of high seas.

The 111'MOD is for PP O2 of 1.4 which is the recommended sport diving limit that I am familiar with. I respect that limit when I dive nitorx, but I do know others who plan their dives based on a PP O2 of 1.6. 127' is within the 1.6 limit. It's not something that I would plan to do, but it's not something that I would find extremely concerning if an experienced diver chose to do it.

When I first looked into mixed gasses a couple of decades ago, I worked off the Navy manual, which allowed PP O2 up to 2.0 at the time. I consider that limit to be genuinely dangerous. I believe that the current Navy limits are based on the physical reactions of individual divers, but I don't have the details on that available to me at this time.

When I fill a nitrox tank, I mark it with MOD for both 1.4 & 1.6. I plan to dive within the 1.4 limit, but if I have an emergency, like another diver in trouble, I will go to 1.6 as is necessary. For that reason, I like to know my 1.6 limit before I hit the water. To date, I have never blown past 1.45.

 

[gamon]

Two. 32% nitrox Diver planning a 127 foot dive. The MOD on that baby is 111 feet. Just saying. The dive op changed the dive at the last minute (we were on top of the dive) because of high seas.

Mod for Ean32 at 1.6 is 132 feet. Nothing at all concerning about that.

 

[Subcooled]

Mod for Ean32 at 1.6 is 132 feet. Nothing at all concerning about that.

True, maybe.

Maximum operating depth is a complicated thing. 1.6 is not bad in certain situations (very relaxed and with air breaks, that is)(e.g. deco stop).
For rebreathers (extended bottom times) a value of ppO2=1.3 or less would be important.
I do know a former rebreather diver, who burnt his lungs with oxygen and cannot dive anymore.
The general recommendation is 1.4. It is normally safe for OC.
See, there is no hard limit.
It depends.

We might say that ppO2=1.4 ATM is max, but it is only max if you want a certain security threshold for a certain time at a certain activity level with a certain level of overall health. It's all about statistics. And because it is statistics, it is probabilistic, and thus you can be "safe" and the **** may still hit the fan. The ppO2=1.4 is extremely safe for any OC diver, though. Above that value risks start to accumulate.

I have also seen historical O2 tables down to ppO2=2.2 ATM with max allowed bottom times listed (assuming you are young and fit).

__________
I had to breathe 50% O2 at 30m/100ft once. That's ppO2=2.0 and I am still alive. You can guess that my bottom time was not very long and that this incident wasn't really planned, but it was certainly better than drowning. It all depends on ppO2, activity level, time, and your body, and some luck.

 

[Germie]

I was last year on Curacao and signed in for unlimited diving with my cave instructor card. After 2 days of solodiving they wanted a solodive card as I was diving solo all the times. (you just rent tanks there, put them in a rental car and go diving where you want). I said my cave and trimix instructor cards are more than a self sufficient card as you need to be self sufficient/self reliant when doing tech. They didn't know and it was fine then.

A lot of diving centers don't know that tech certs mean that the diver must be able to dive self reliant. That doesn't mean solo, but they know the same 'tricks'.

When needed I can show online that I am self sufficient instrutor, but I try to avoid to learn dive centers new things about the tech certs that they most times don't know because they only do sportsdiving to 40m within ndl.

The divecenter was not saying anything about me when I took 3 cylinders for a solo housereefdive

 

[drrich2]

A lot of diving centers don't know that tech certs mean that the diver must be able to dive self reliant.

There are 2 issues of potential concern here.

1.) Whether you have the capability worthy to be trusted to dive solo competently. You do.

2.) Whether a jury will be convinced of that after you die on a solo dive, and someone tries to sue claiming the dive center shouldn't have rented you tanks to solo dive when you weren't certified for it.

I wonder which concern is the main driver for dive center concerns over this issue? And since Curacao isn't the U.S., I wonder how law-suit friendly their society is?

You bring up an interesting issue - what non-solo diving certifications ought to be counted as equivalent to it?

When I got my SDI Solo Diver certification years ago, it was intended for solely recreational solo diving (I have no technical training or cert.s anyway). There are no technical level solo cert.s are there? People who do solo tech. dives don't traditionally require a solo cert. for it, if I understand correctly.

 

[Akimbo]

2.) Whether a jury will be convinced of that after you die on a solo dive, and someone tries to sue claiming the dive center shouldn't have rented you tanks to solo dive when you weren't certified for it.

Exactly. The only reason I got a solo card was to let the boat (captain, owner, company, etc) off the liability hook.

 

[tursiops]

When I first looked into mixed gasses a couple of decades ago, I worked off the Navy manual, which allowed PP O2 up to 2.0 at the time. I consider that limit to be genuinely dangerous. I believe that the current Navy limits are based on the physical reactions of individual divers, but I don't have the details on that available to me at this time.

From USN Diving Manual, Rev 7, Section 10-3:

Normal working dives that exceed a ppO2 of 1.4 ata are not permitted, principally to avoid the risk of CNS oxygen toxicity.​

 

[raftingtigger]

Never been turned down, never been asked about card or even equipment. California dive boats don't care. Nobody has ever asked to see a drysuit certification card either.

I started diving dry in 1980 and have never gotten a card for it. Only thing I can't do is rent one (I have 4, why would I want to rent?). I started the PADI Self-Reliant, but could never get the instructor to finish it.

DMs are really solo divers (as are instructors) often with impediments (students). Neither are trained OR generally equipped for proper solo diving. I have carefully trained myself (via books) and at this point probably have more knowledge AND experience in solo diving than most instructors I could take a class from.

For grins and giggles I often use my first certification (NASDS OW from 1971 with maiden name and no picture). I have yet to have that not be enough. Yes, I have MUCH higher certs (DM, Tech) that I can show, but haven't needed to.

 

[Wibble]

When I got my SDI Solo Diver certification years ago, it was intended for solely recreational solo diving (I have no technical training or cert.s anyway). There are no technical level solo cert.s are there? People who do solo tech. dives don't traditionally require a solo cert. for it, if I understand correctly.

That's the point: recreational vs technical.

Technical diving requires the diver to be able to cope with hard and soft overhead environments. This means that the diver must be able to plan for and cope with failures during the dive. In essence this is the same as "Solo Diving".

Put it another way; SDI (a recreational agency) have a two day workshop for Solo Diving, basically it's a two day assessment of the diver's skills; the diver should already have those skills.

Contrast this with the weeks of training for technical diving, especially if deep, cave or CCR, where the diver plans and executes various failures and 'perils' both during the course and subsequently.

Handling failures, skills refinement and self-sufficiency is the whole raison-d'etre of technical diving.

 

[raftingtigger]

Agree with the last two veteran posts. But, of course we all know (at least from reading on SB) that for some dive ops it wouldn't matter if you had 10,000 solo dives, you can't dive with them without the card. As well, if you are looking to take the course and get the card it doesn't necessarily mean you are not ready to solo dive. That may be the case with myself, as an instructor friend of mine is now qualified to teach it. I may take it with him next year or so and have been solo diving for over 10 years. Someone may just have a lot of money and be a card collector. It may be of interest as well to see exactly what it is in the course that one supposedly doesn't know yet (stuff other than to be redundant and not be stupid).

In my case I can tell you exactly what is in the PADI Self-Reliant and the SDI Solo courses as of about 8 years ago. I 'took' both on paper by reading, studying, and digesting all their material. What I didn't do was get an instructor to pay attention to me long enough to verify I could do all of this at that time. At this point I have been diving with MANY GUE Tech divers who will attest to my competence as a diver and solo capabilities. Paying for a card is a waste of my money. Never been asked for it, never likely to in the places I go. If I'm asked, I tell them I am solo qualified and equipped.