Thinking to go Solo - some questions

[leadduck]

This discussion is focused too exclusively on equipment and configuration for my taste. As long as you do NDL dives shallower than 25m, equipment failure need not be your main concern. The main risk of your solo diving won't be equipment failure, but human body failure, i.e. medical issues.
Say, you felt sick under water and still managed to initiate the CESA, passed out and are now floating face down on the surface. Who'll pull you out and call 911? So you better avoid remote sites and prefer crowded places. One friend's wife always joins him for his lake solo dives; she walks the dog and watches his bubbles.

 

[stepfen]

This discussion is focused too exclusively on equipment and configuration for my taste. As long as you do NDL dives shallower than 25m, equipment failure need not be your main concern. The main risk of your solo diving won't be equipment failure, but human body failure, i.e. medical issues.
Say, you felt sick under water and still managed to initiate the CESA, passed out and are now floating face down on the surface. Who'll pull you out and call 911? So you better avoid remote sites and prefer crowded places. One friend's wife always joins him for his lake solo dives; she walks the dog and watches his bubbles.

That's a very good point that I haven't seen being discussed in SB. Thanks for bringing it up.

How much help your friend's wife can really offer? Are you sure it will be enough?

Below I will get a bit harsh, maybe too much. But that's the way I see it. Feel free to correct me if I am wrong.

Following your scenario that somebody surfaces unconscious face down, say 200 yards from shore as a result of a serious medical condition. Can his wife or a random person on shore swim 200 yards to get there? In time? Does that person know how to help? Will she/he mentally be ready and capable to help? Can she/he tow the victim to shore and out of the water? Can she/he offer first aid? I don't know, but chances seem very low to me.
As for 911, by the time they arrive in your scenario I think they won't be able to offer much other than helping recover the body.

If I get a serious medical problem (we are talking about heart attach, stroke or similar conditions) chances for survival are small even topside. Under water I highly doubt that even a large group of specially trained buddies around me can do much. I'm about 220lbs - just to get me out of the water will be a big PITA for them.

To me the main difference seems to be that if people are near me if such thing happen, they will post the info to the A&I forum in SB so that you guys can know how I died. Having people around also helps to locate and recover the body. Apart from these, I'm very skeptical on how much more help I can get.

Should I abandon diving based on this? But then I think I should also stop driving, walking on the street, getting out of bed etc. Even spending my whole life in an ICU might not be safe enough.

For me medical conditions is part of the risk I accept when I go diving. I have to improve myself as much as I can (my physical condition is far from ideal), but apart from this, I feel that not much can be done.

Now, here is how I plan to deal with my dives.
Having somebody nearby is not an option for me. So just before I'm ready to splash, I plan to let my wife know my position (GPS) and estimated time to finish the dive. Usually my dives are ~1 hour long hence if she hasn't heard from me within say 90-120mins she should start to worry and ask for help. By that time it will probably be too late for me, but at least they will know where to look for me.

I'm very curious to hear what other people think of these.
Thanks

 

[stepfen]

I find my 40 cf pony (slung on the right side because I dive an i3 BC) works for me. For now. I've practiced ascents in pool, and will practice ascents from about 35 feet this summer. My overall goal is wreck diving in BC and in the Great Lakes, at about 100 ffw, so I'd prefer more air over say a 20 or 30 cf pony. My SAC/RMV dictate a bigger pony, which doesn't bother me because it doesn't affect my trim (the AL40) that much and I'd rather have more than less.

Isn't an AL40 a bit too much for the task?
Sorry for using metric units below, I will convert to imperial at the end.
I have a SAC of ~15lt/m (ranging from 12 up to 18lt/m) . I will use 20lt/m (0.7cuft/m) throughout to compensate for higher breathing rate.
Assuming that at a depth of 30m (100ft) I get a catastrophic failure of say the 1st stage hence no more air from my main tank.
- At 30m (4atm) I consume 4*20 = 80 lt/m. Let 1minute to short things out, hence at the bottom I'll need say 80lt.
- Ascent from 30m to SS (5m): Mean depth 17.5m (2.75atm) for 3 minutes: 2.75*3*20= 165lt
- SS 3 minutes @ depth 5m (1.5atm): 1.5*3*20=90lt
Hence in total I will need 335lt (~11.83 cu ft) of air including a safety stop. A 3lt tank at 200bar holds 600lt (21.19cu ft) i.e. almost double. I think over there the corresponding tanks are 19cu ft. Isn't it enough? BTW Is there such thing as enough air?

My concern is weight topside. I usually carry a (medium sized) camera with strobes etc and my entries are occasionally from difficult-ish rocky shores. Having to carry a 40cf pony on top of everything else sounds a bit too much trouble.

Due to weather here, my solo training where I hope all these will be addressed and tried in practice is being postponed. I can't wait.

 

[JohnnyC]

No one ever died from having too much gas. 40's are easy to carry. 40's are better if you decide to start carrying decompression gases in the future. Doesn't mean it's the right tank for you though.

You're saving an inch around, 2 inches tall, and 4 pounds by getting a 19 over a 30, an inch around, 7 inches tall, and 7 pounds over a 40.

A 19 goes from 2 pounds negative when full to a little less than 1 pound negative when empty. A 30 will go from 2 pounds negative to neutral, and a 40 goes from a pound negative to 2 positive. BTW a 19 holds 18, a 30 holds 29, but a 40 actually holds 40 cuft. of gas. Realistically none of them will be any different for your use. Pick the cheapest, make sure you never run out of gas.

Oh, and get trained. Instructors gotta eat too.

 

[J-Vo]

I'll add a pro to the AL40 recommendation. They stand tall enough that you don't have to bend over to pick them up. This completely nullifies the extra weight as far as I'm concerned.

 

[stepfen]

I'll see how it goes during the training. I'll try to get some dives with both options. For long term AL40 seems better option, but for now I might settle with the 19.

I'd like to hear more commends about the other issue (possible medical issues) from more experienced people if possible.

Thanks again.

 

[Bob DBF]

The best choice of pony is the one you will take. I started using one on deeper dives as I got older, and will probably continue to revise what I consider deep over time.

No one ever died from having too much gas.

I completely agree, however I'm not a fan of dragging along extra gear. If I need a big pony, I can rig an Al 80 or an old steel 72 in nothing flat, if it isn't already. I have to be planning something pretty sketchy to need that much air.


As far as medical issues, you have to decide whether the risk is worth it, as you putting yourself in an environment that will make a medical issue hard or impossible to treat, even with a buddy.


Bob

 

[markmud]

I have to be planning something pretty sketchy to need that much air.

Yeah, my style of diving does not require that much gas. The smaller ponies go with me because they are convenient. The bigger ones would get left in the garage.

To each his own!

markm

 

[stepfen]

Hello again,
About two months after my initial post I'd like to give an update. I just finished with the training. Eventually my instructor did pretty well in over-sale and convinced me instead of Solo to do an SSI XR Nitrox instead. On top of the course we also discussed a bit about solo procedures etc.
His argument was that with the advanced nitrox course (plus a bit of chatting) we'd cover all I needed for solo plus several new and promising things (deco etc). Anyway I like to have knowledge of the next step of whatever I am doing. So a glimpse of deco/tec procedures sounded attractive to me.

First let me tell you my instructor's points of view in matters previously discussed in the thread:
- Slung ponies: According to him, this is not a good idea because it creates the habit of regarding whatever you slung under your left arm as a redundant air source. In tec dives, that's a deadly wrong habit. For this reason he suggests at minimum:
- h valve: In theory enough air reserves should be carried to allow enough time to isolate the leaking side. In my case I can reach and somewhat manipulate my valves, but to troubleshoot a real serious leak? It feels like an eternity just to think about it. No freaking way I'll rely on this.
- Of course the safest option is doubles (BM or SM), but for reasons I explained earlier for these are not going to happen any time soon. I also realized the necessity of a dry suit for such dives (and the list goes on), but dry suit joins my long future TODO list together with the doubles.

I liked and enjoyed the course as during it I learnt and realised lot's of useful stuff.

Although I liked the accelerated deco with the 50% nitrox (dive plan was something like 20 min at 120ft/40m and about 20 min for ascent, deco and ss), I don't really have reasons for such dives (as yet) hence I will keep my dives within the NDL/100ft/30m limits.

Based on these I decided to get a pony for my solo dives exceeding 50ft/15m or so . Size will probably be 7lt (AL50?). I did the full course with AL80 stage and I had no problems at all with it both underwater and topside, hence I figured a 7lt will be a good choice.

As for my instructor's worries (mixing pony with deco gas etc) it is clear to me now that tec dives without doubles and dry suit are a big no. I might be able to get these at some point, but that sounds too far from now. Until then I will try to dive as safe as I possibly can within the limits of what I have.

BTW I am looking for a good book on solo. I can find SDI solo manual but not in Europe. eg DRIS has it, but with postage to Greece it gets almost to 100$! Nothing reasonable in ebay either.

Are there any other options available ? I don't mind e-books.

Thanks once for all the replies!

 

[scubadada]

Hi @stepfen

I'm sure you will find your class valuable. It will do nothing to help you dive solo if an operator requires the cert (SDI, PADI, SSI, IANTD...)