[cedricverdier]

Hi all,

Just to start a new thread, please find a new article: How to make Solo Rebreather Diving safer?

This article is published in the library here:
http://www.rebreatherworld.com/rebre...html#post52309

or you can download a complete version on my web site at
www.cedricverdier.com/articles.html

I know it's not politicaly correct. GI3 will never like that. Nobody should endorse Solo rebreather diving.

But the fact is: there's quite a lot of Solo rebreather divers.

So I would like to have some feedback from these solo rebreather divers:
- how do you plan your dive (compared to a dive with a buddy)?
- do you use any specific equipment?
- what kind of dive profile in what kind of environment?
- is there a way to improve safety?



Cheers

[Nicholas von Rosen]

Hi There...

My budy and I always agrees on a bottomtime before we dive. Once at the wreck we seperate and do our dive solo. We meet back at the rope at the agreed time time and do our deco...

If the buddy dosn't show up we start lokking...

Nick

[cedricverdier]

Quote: (Originally Posted by Nicholas von Rosen)

Hi There...

My buddy and I always agrees on a bottomtime before we dive. Once at the wreck we seperate and do our dive solo. We meet back at the rope at the agreed time time and do our deco...

If the buddy dosn't show up we start lokking...

Nick

Two solo divers diving in the same ocean at the same time but with a kind of back-up plan. Good idea!
Just a question: do you have any way to communicate with the other diver if for any reason (bail-out, bad feeling, etc) you decide to ascent before the agreed time?

Cheers

[jmurba]

I know it's not politicaly correct. GI3 will never like that. Nobody should endorse Solo rebreather diving.
Hello Cedric,

My opinion is the following one.
solo diving is not admitted in diving community because of the necessity of sharing gas and because of the danger of fainting underwater due to use of narcotic gases (air).
when we switched to trimix and tek diving, gas redundency and non narcotic gases made solo diving not more dangerous then solo motorway driving 150km/h.
In my club on the french riviera we were even allowed to dive solo !!!!yes yes cedric (((-it would no be policicaly correct to tell you which club it was(((-
Soon later we switched to scr and ccr kiss...and there we discovered knew hazards...hypoxia and co2 hits....that made it again more likely of fainting.
This new hazards lead me to go back to buddy diving hopping that my buddy will press my o2 addition valve in case of necessity...

regards

jean mi

[Mark Chase]

Regardless of it being OC or CCR, solo diving will always be more dangerous than diving with a confident and accomplished dive buddy who has a modicum of bravery / ability to work under pressure.

Nothing you do preview, during the dive or to your equipment, will alter this fact.

However, diving with an incompetent buddy or worse a buddy who appears competent but panics under any kind of pressure situation. This is far more dangerous than diving solo.

CCR divers are unique in the fact that they can more easily pass out on the unit. This one situation can easily be fixed by a competent buddy if its a P02 issue and although harder, it should be possible to fix a C02 problem as well.
In the situation of C02 the diver will be so narked that a competent diver may be able to see signs that all is not well, before the hit takes full effect.

02 convulsions are a massive problem for any diver 0c or CCR unless the diver is using a full face mask or a gaged regulator. From what i understand of 02 hits a solo diver still wouldn't survive this despite the gag or ffm.

What can be done to make solo diving safer?

Big improvements in pp02 monitoring equipment (starting with the cells). Cheaply available (preferably on unit) cell testing equipment that can take a cell through air and up to 2.0pp02 on dry land. A c02 analisor on the CCR would help a lot as well.

PERSONAL SOLO DIVING

When I solo dive the unit I am far more cautious in all aspects of the dive. I will avoid potential entanglement and entrapment situations. I will also avoid task loading so no video unless conditions are perfect and ill try and follow the wreck rather than lay line or ill follow someone else's line.

I will run the dive well inside CNS limits possably dropping the set point on deeper dives. Dropping the set point also gives more time to react to solenoid issues should they occur. Equipment is meticulously checked before any dive so that makes little or no difference. I run solo bailout on all dives now so that doesn't make any difference however it is more likely i would bailout to OC on a solo dive than on a buddy dive. On a buddy dive id alert my buddy to a problem and probably try and fly the unit out.

I strongly believe that any diver not mentally prepared to be solo on a dive is inadequate to the task and using another diver as a crutch. However this fact doesn't stop me realizing diving with a competent buddy is always the best policy.

ATB

Mark Chase

[Nicholas von Rosen]

Quote: (Originally Posted by cedricverdier)

Two solo divers diving in the same ocean at the same time but with a kind of back-up plan. Good idea!
Just a question: do you have any way to communicate with the other diver if for any reason (bail-out, bad feeling, etc) you decide to ascent before the agreed time?

Cheers

Hi again

We always carry our own bail out gas, - and we both carry the same back up tables with both CCR and bail out deco times...

In some strange way our interests are the same, - so it's rather rare that we are seperatete more than we are able to shout to each other... - other than that we got no communication... - but it's a good idea...

I think I will arrange that we get some sort of plate with our name... - we can leave it at the rope when we arrive at the wreck, - and take it with us up when we leave... - In this way one is able to se if the buddy "has left the building " (asuming he uses the rope off course )

Nick

[NickK]

Quote: (Originally Posted by cedricverdier)

But the fact is: there's quite a lot of Solo rebreather divers.

So I would like to have some feedback from these solo rebreather divers:
- how do you plan your dive (compared to a dive with a buddy)?
- do you use any specific equipment?
- what kind of dive profile in what kind of environment?
- is there a way to improve safety?

Thank you Cedric for bringing this topic. Personally, I think that it is one of the most seriouse and important aspects in scuba diving (especially Rebreather), and quite controversial thought.

Most instructors will tell that solo diving is very bad practice and would not
discuss it. Will be very nice to see different points of view and listen to the experience here (Rebreather World).

After beginning of my diving few years ago I started to realize that there are cases when air consumption (on OC), buddy's physical condition,
level of experience e.t.a can create unpleasant dive situation. These factors cannot contribute to safe diving any way. Second is a mental factor. Remember my first solo in cold murky altitude lake. To tell the truth it was very hard to step over myself to make that first dive. And the moment when one of the first dives in Pacific Ocean me and my buddy were separated due to reasonably strong current I decided to spend more time to be ready for solo diving at any time.

Diving solo with my Evo calling for more preparation time evening before the dive (as any rebreather in general), and doing shore dives I take more time in depth range 6-10 m to make final check on Rebreather, bail out and very carefully "listen to my body feelings". After 2-4 min, if all checks ok I go deeper.
55-70 min when I slightly start to feel cold slowly retuning to the shore.
Mental preparation consider #1 in solo diving. Trying think through the upcoming dive, "work out through emergency procedures". Deploying lifting bag and work on buoyancy (having four points to control at that time) is second after controlling your Rebreather.

At this moment using original Evo configuration with 1 L dry suit and 6 L bail out air bottles. Lifting bag, reel, knife (two) main and back up lights.
At this time, while learning to dive Rebreather, dives will be limited to 40 m max with
air dil and bail out.

Safe solo diving,

Nick

[Micko]

Cedric how about yourself on solo diving?
And if you do what depth do you limit yourself to?
Runtimes?


My self i like to let a person know if or when i choose to solo dive.
Let them know location ;;;time of entry;;; and exit time..
Then i will phone this person as soon possible.

[db8us]

I did my last solo-dive back in the 90s.
Today, i like to share the experience after the dive with my buddy.
Also a competent buddy is better than a buddy-bottle, since i have never seen a tank with eyes, a brain, hands and feet !


Michael

[cedricverdier]

hi Mark,

I really appreciate your comments. A lot of good things

Quote: (Originally Posted by Mark Chase)

In the situation of C02 the diver will be so narked that a competent diver may be able to see signs that all is not well, before the hit takes full effect.

A CO2 hit could happen at shallow depth as well (so no sign of narcosis). I had a bad CO2 in a shallow cave during a very long dive. I hardly think that anybody could have noticed anything before I actualy switched to OC and fixed the problem by myself.

Quote: (Originally Posted by Mark Chase)

02 convulsions are a massive problem for any diver 0c or CCR unless the diver is using a full face mask or a gaged regulator. From what i understand of 02 hits a solo diver still wouldn't survive this despite the gag or ffm.

If the airway is well protected, why not? the convulsing diver has obviously to be brought back to the surface at one point, but this could wait for a while...

Quote: (Originally Posted by Mark Chase)

Big improvements in pp02 monitoring equipment (starting with the cells). Cheaply available (preferably on unit) cell testing equipment that can take a cell through air and up to 2.0pp02 on dry land. A c02 analisor on the CCR would help a lot as well.

Very true! We're all waiting for that.

Quote: (Originally Posted by Mark Chase)

I will run the dive well inside CNS limits possably dropping the set point on deeper dives. Dropping the set point also gives more time to react to solenoid issues should they occur.

Very good point (to be included in the next version of the article!)

Quote: (Originally Posted by Mark Chase)

I run solo bailout on all dives now so that doesn't make any difference however it is more likely i would bailout to OC on a solo dive than on a buddy dive. On a buddy dive id alert my buddy to a problem and probably try and fly the unit out.

Why flying manually when you are with a buddy and not when you are on you own?

Thanks for sharing your experience

Cheers