Solo diver vs Self-Reliant diver

[gordonscuba]

While seeming massive, a ruptured HP Hose is an inconvenience only. Look at the actual fitting that goes into the first stage. It is a tiny pinhole (which is the reason you can diagnose a partially closed tank valve by looking at your spg while taking a breath off your regulator). Search a bit about actual rates of flow and time to empty a cylinder for HP and LP hoses.

A LP hose failure is a whole different situation, and possibly a deadly one...

I agree that those flow-limiters are a fine thing. (We have them on the oxygen side of our ccr bottles too, so that you have time to deal with a stuck-open solenoid before the ppo2 rises too quickly.) The time to empty a full cylinder would be several minutes, but of course when this happens you don't have a full cylinder. Realistically, it might take an average, slightly narked, diver a minute (plus or minus), to understand why they were hearing the sound of bubbles from an unseen place, make the decision to thumb the dive, and start their ascent.

This was written in response to a post about solo deep diving without a secondary air source. Someone posted along the lines of "if the equipment is okay as I start the dive in shallow water, I've validated the gear is working and I continue to 130 ft, so I don't need a secondary air source". I just wanted to point out that failures of various kinds in the middle of a dive, while rare for well-maintained gear, still happen with enough of a frequency that everyone diving long enough has seen one. Hence "start the dive shallow and continue progressively to deeper water" is not an approach to gear redundancy that solo divers should be advocating IMHO.

 

[SlugLife]

Realistically, it might take an average, slightly narked, diver a minute (plus or minus), to understand why they were hearing the sound of bubbles from an unseen place, make the decision to thumb the dive, and start their ascent.

When I had a hose come loose at my 2nd stage, 30ft deep (not nacred), bubbles in my face, it took me a moment to realize what went wrong, got task-loaded trying to find my octo and just went for the simpler option straight to the surface.

If the rupture is behind you, I could see that catching a diver off guard. "What is that sound?" "Where is it coming from?" "Is it me or another diver?" etc.

Someone posted along the lines of "if the equipment is okay as I start the dive in shallow water, I've validated the gear is working and I continue to 130 ft, so I don't need a secondary air source". I just wanted to point out that failures of various kinds in the middle of a dive, while rare for well-maintained gear, still happen with enough of a frequency that everyone diving long enough has seen one.

Personally, I find redundant air is the simplest and most reliable way to massively increase the safety of my diving.

I mean sure, I could make sure every piece of equipment is serviced precisely annually, follow every drop of advice and training, avoid anything remotely dangerous, avoid using swivels and flex-hoses, practice CESA, check pressure every 30 seconds, always dive with a buddy, or even join the church of GUE. However, in the event my only air-source has a critical issue for any reason (including my own behavior), I know I'm prepared, because my redundant air goes with me on EVERY dive.

Plus redundant air is helpful for other unexpected issues, like entanglements. More air is more time to resolve almost any issue.

 

[34109411]

I used clear tubing (rather than opaque fuel line) for the "handles". And my bolt snaps have closed ends that are larger (because I was wearing thick, cold-water wet gloves for Great Lakes diving at the time).

I used bungee cord (rather than, say, bands cut from a motorcycle inner tube) to secure my 40" regulator IP hose.

Oh, and avoid the cheap galvanized (?) hose clamps.

Decide whether you will use a button gauge (of whatever size) or a B&G SPG. If the latter, decide how you will attach it (short HP hose?) and how you will secure it.

Google to see various examples of how people do things. For example, some people will thread the hose clamp through tube webbing. And don't forget to address the "free" end of the hose clamp (so it's less likely to catch on things and/or hole your drysuit).

Good luck.

rx7diver

yes i am thinking of i should get a small button spg or one on a hose... i am always wondering why we use only just one clamp on the bottom of the tank and why we could not put one on the top (near the neck). Anyone knows ? This will save the trouble to run a cord from one to another and will not need the rubber tube as well.

 

[34109411]

That seems a bit expensive, unless they're crazy good. Check Dive Gear Express. I spend about $5.5 USD on my giant 4 or 5 inch bolt-snaps, and less $ on the smaller ones. Though I usually buy bulk packs of smaller bolt-snaps, just because I use so many of them.

If you want to spend a little more than $5, Piranha has some Easy Grip Swivel boltsnaps, that are great for cold-water diving, gloves, or difficult-to-reach bolt-snaps. I use a few on my SideMount butt-pouch.

The other thing that can be useful, is tubular webbing, to go around the hose-clamp to reduce scratches on the tank. You can get it on Amazon, ebay, or DiveGearExpress as well. I think 1-inch tubular webbing is the right size.

My tank-bands were made from bungie, although that does have a tendency to "roll" a little. I have experimented with elastic, but didn't have better results. The ones you get with commercial solutions are probably slightly better. You don't have to use the elastic band, but it can be useful if you sling the tank (front or side mount) for retaining the hose.

i am in canada exchange rate is killing us to buy in the USA. DGX charge a lot for shipping. Bolt snap in my part of the country are really 15$ each minimum.

 

[SlugLife]

i am in canada exchange rate is killing us to buy in the USA. DGX charge a lot for shipping. Bolt snap in my part of the country are really 15$ each minimum.

I don't know how to check shipping to your location, but maybe try amazon. Search for "marine bolt snap." This one might be an option.

 

[34109411]

dgx charge about 50$ usd for international shipping otherwise you need to buy for 200 US to have free shipping outside US.

 

[MyBuddy]

dgx charge about 50$ usd for international shipping otherwise you need to buy for 200 US to have free shipping outside US.

If you’re not spending more than $200 usd per order are you really even buying scuba gear?!?

 

[rverma]

i am in canada exchange rate is killing us to buy in the USA. DGX charge a lot for shipping. Bolt snap in my part of the country are really 15$ each minimum.

I bought all my bolt snaps from aliexpress and they’ve been working just fine for the past year. No signs of corrosion or anything, and cost about 5$ each incl shipping. Another good source for cheaper stuff is piranha dive manufacturing.

 

[34109411]

If you’re not spending more than $200 usd per order are you really even buying scuba gear?!?

lol

 

[chrisjur]

The certs are all for recreational solodiving. The bigger problem is that divecenters don't see a technical cert as a solo cert, but every technical diver must be able to be self reliant or self sufficient. I had a discussion with this, I showed a full trimix and full cave instructor card and then the discussion began. I have a self sufficient cert, but I wanted to open the discussion. At the end, they did not know about technical diving and that every technical diver must be able to close valves, etc. So it was their knowledge.

Also a lot of divecenters really don't know about solodiving. And a lot of normal divers also don't know, they just say: it is dangerous and forbidden because it is written in books 'never dive alone'. I tell every open water student that solodiving is something that can be done if they get more experienced. The reason that I tell it directly that there is a chance that they will see me entering the water solo when I am not teaching.

A lot of divecenters have to learn and to accept that solodiving is safe.

You’re very much correct. An experienced tech diver has far more “solo” experience and relevant skills than someone who has taken a 3-dive Self Reliant class.

I brought this up with the owner of my regular dive shop. His explanation was simple: Insurance. He says that his insurance will
not allow patrons to solo dive without a solo/self-reliant certification, regardless of how many technical certs or thousands of dives someone has. They attempt to be overwhelmingly accommodating to their regular dive customers, but solo diving is still a no-no if you don’t have the cert. No exceptions.