Redundant Systems

[gcbryan]

There's a lot of talk regarding using pony bottles or not using them. Using no computers or using one computer or two computers.

In other threads there's talk of not looking at a gear based solution. But why not?

I don't mean that gear is a solution. Of course you need training, experience, etc not just with the gear but with the whole approach to diving but.... just looking at the gear aspect of diving why not embrace redundancy completely?

Most people who dive at night have two lights rather than one light and your buddy is your backup light. Many people have two computers or a bottom timer and a watch. We carry two second stages but somehow carrying another first stage and slung bottle is too much? Some argue that carry two computers is too much. That's just carrying another set of backup gauges.

Someone asked where do we draw the line? Can one forgo a pony on a 8 foot dive, how about 30 feet and so forth? If you dive a redundant system there is nothing wrong with a pony on an 8 foot dive. You can certainly not do it as well but you can drown in 8 feet of water if you become entangled.

Many people dive doubles all the time simply because they like to dive the same setup all the time. Very few people have much to say about this if that's the reason they are doing it. Slinging a pony is the same. Once you have a redundant system you can argue that you might want to just use that system all the time.

I see this derided from time to time but I just wonder why more people don't see this as a legitimate way to dive just as many other differing ways are legitimate. Most people agree that this is the way to go if one is diving solo but otherwise they have a problem.

I always wonder when everyone reaches the same consensus using the same arguments (sometimes seemingly without thinking for themselves).

Flying, people use check-lists to promote consistency. If the lights don't work but you're not planning on flying at night you still don't take off. You want a complete system. Why are some so into changing their scuba gear (right gear for the job) from dive to dive. There are certainly valid arguments for doing so but there are equally valid arguments for not doing so. In scuba for some reason there seems to be one way to do things and everyone other method is flawed for some reason. I don't get it.

I don't think there are enough people in scuba who would tell the emperor he had no clothes on. I think after while it would come as a shock to some that the emperor actually had no clothes on. I think they actually are starting to mentally clothe the emperor.

The earlier thread on Risk Analysis was a good one and one that has always interested me. We train to eliminate risk and then what do we do...penetrate wrecks (and lecture others on safety)! It's human nature but it is interesting. There's a lot of logical inconsistency in many scuba hot topic threads.

 

[Web Monkey]

In other threads there's talk of not looking at a gear based solution. But why not?

Stuff you don't have, can't break.

I know it sounds silly, but it's true in both software and diving. If it's not there, it can't give you trouble.

Using a (well-trained) buddy for backup means you not only have an extra of pretty much everything, but you also have an extra brain, and someone to poke you in the ribs and say "no" if you're about to do something dumb.

Terry

 

[gcbryan]

We're not talking about diving without a buddy. The only thing we really have to have underwater is air (gas) and it's the one thing that we don't frequently carry a redundant supply of.

Why backups for lights but not air?

Also, if simplicity was the issue no one would have cannister lights or scooters.

 

[NudeDiver]

All of this stuff about buddies is predicated on knowing who your buddy is going to be for the dive, knowing that your buddy is someone you can depend on, and other such stuff. It's great if you're diving with people you know and trust. But many times, you have no clue who your buddy is going to be or what he is going to do underwater. That's a reality for many people, on many dives. Hell, for me, with my puny 85 dives, only maybe 15 are with someone I planned to dive with ahead of time (and 4 of those were certification dives). That leaves 70 dives with total strangers, with unknown training, skills, abilities or attitudes. All things considered - being self reliant to the greatest extent possible is not a bad way to go.

 

[DaleC]

Many people have a group mentality.
This comes from a natural, human sense of insecurity.
To reduce the insecurity, they reinforce the group.
The best way to reinforce the group is to create an external enemy.
In SCUBA a person is not the enemy; outside gear, methods and associations are.

It takes a secure mind to be able to step outside the group, look at an alternative method/mode and acknowledge that it may also be valid. For an insecure mind doing this, in some way, is seen as diminishing the validity of ones own method/mode.

 

[NudeDiver]

Many people have a group mentality.
This comes from a natural, human sense of insecurity.
To reduce the insecurity, they reinforce the group.
The best way to reinforce the group is to create an external enemy.
In SCUBA a person is not the enemy; outside gear, methods and associations are.

It takes a secure mind to be able to step outside the group, look at an alternative method/mode and acknowledge that it may also be valid. For an insecure mind doing this, in some way, is seen as diminishing the validity of ones own method/mode.

My Zen meter is pegging

 

[Rainer]

All of this stuff about buddies is predicated on knowing who your buddy is going to be for the dive, knowing that your buddy is someone you can depend on, and other such stuff. It's great if you're diving with people you know and trust. But many times, you have no clue who your buddy is going to be or what he is going to do underwater. That's a reality for many people, on many dives. Hell, for me, with my puny 85 dives, only maybe 15 are with someone I planned to dive with ahead of time (and 4 of those were certification dives). That leaves 70 dives with total strangers, with unknown training, skills, abilities or attitudes. All things considered - being self reliant to the greatest extent possible is not a bad way to go.

No one is suggesting that an Insta-buddy is a true redundant gas source. For recreational dives, I'm happy just relying on my similarly trained buddies. I truly think they're more reliable than just slinging another bottle. If I were in your shoes, however, I'd probably be rocking doubles or a pony bottle on these same dives. Different approaches to safety. Do what works for your situation.

 

[TSandM]

I think that, all too often, people draw lines in the sand when they shouldn't be drawn.

For example, I don't do normal recreational dives with redundant gas, or redundant gauges. That's due to two things: One, the likelihood of a catastrophic gas loss or gauge failure is very low, and two, I surround myself with people who I know are trained and reliable to provide gas if I need it, or to help escort me out of the dive should my gauge quit. My choice of solution is a part of a much bigger picture, and if you change the initial conditions, the solution might be different.

I have said before that, if I traveled a lot and dove off boats with insta-buddies, I'd seriously consider a slung bottle, especially for deeper dives. I'm the same diver, using the same care to plan my gas and monitor it, and the risk of equipment failure is still very low, but the solution I usually rely upon is no longer something I can be sure is available. At that point, an equipment solution may be better than a procedural solution.

With every piece of redundancy, one has to ask: How likely is a failure of the primary item? (With lights, the answer is "high".) Then, how serious an impact will that failure have on my safety? With lights and buddies, the answer is "low". With gas and no buddies, or no reliable buddies, the answer is "high". If the failure is likely, or the consequences are dire, then some kind of redundancy ought to be considered. Since I can't reasonably use my buddy's light, I carry a spare (or two at night or in overheads). I CAN use my buddy's gas, so I don't always carry a redundant supply, but I would if I worried that that buddy's gas wouldn't be available.

One could carry a redundant everything -- do every Edmonds Underwater Park dive in doubles, with three lights, two gauges, a spare mask, and two scooters. But it wouldn't make diving very much fun, and it wouldn't add much to safety, either.

 

[Jorgy]

I dive 2 computers whenever I can, we are a diving family and all have Suunto Computers - 2 Vipers and 2 Gekkos. So, unless we are all diving tighter, I typically always have an extra computer available with the same algorithm available to use. It fits in a small XS scuba weight pouch on my waist. I think it is important backup as my computers are my depth gauges.

I also have a 19 cf pony that I sling whenever I am diving deeper that about 50 - 60 feet or diving with insta-buddies (as I often go to Canada for one-day 2 or 3 tank charter as a last minute solo walk on). I only use the pony when I dive with a single tank, with my doubles no pony.

In Central NY visibility is often an issue and the pony is easy to sling and dive with, so it just gives me a personal sense of extra security. That being said I don't solo dive and I have never had to use the pony.

These redundant items just make me more comfortable and are easy to dive with so for me it is a simple choice, no drama, just what works for me.

Just my thoughts.......M

 

[gcbryan]

I think that, all too often, people draw lines in the sand when they shouldn't be drawn.

For example, I don't do normal recreational dives with redundant gas, or redundant gauges. That's due to two things: One, the likelihood of a catastrophic gas loss or gauge failure is very low, and two, I surround myself with people who I know are trained and reliable to provide gas if I need it, or to help escort me out of the dive should my gauge quit. My choice of solution is a part of a much bigger picture, and if you change the initial conditions, the solution might be different.

I have said before that, if I traveled a lot and dove off boats with insta-buddies, I'd seriously consider a slung bottle, especially for deeper dives. I'm the same diver, using the same care to plan my gas and monitor it, and the risk of equipment failure is still very low, but the solution I usually rely upon is no longer something I can be sure is available. At that point, an equipment solution may be better than a procedural solution.

With every piece of redundancy, one has to ask: How likely is a failure of the primary item? (With lights, the answer is "high".) Then, how serious an impact will that failure have on my safety? With lights and buddies, the answer is "low". With gas and no buddies, or no reliable buddies, the answer is "high". If the failure is likely, or the consequences are dire, then some kind of redundancy ought to be considered. Since I can't reasonably use my buddy's light, I carry a spare (or two at night or in overheads). I CAN use my buddy's gas, so I don't always carry a redundant supply, but I would if I worried that that buddy's gas wouldn't be available.

One could carry a redundant everything -- do every Edmonds Underwater Park dive in doubles, with three lights, two gauges, a spare mask, and two scooters. But it wouldn't make diving very much fun, and it wouldn't add much to safety, either.

Good post.

Just for the sake of argument however how would having two gauges, a spare mask, and three lights take away from the fun of diving at EUP (I'll ignore the two scooters)?

I'm not saying that it's needed but since you already have pockets in your drysuit, having a mask in one pocket wouldn't be noticeable. Having two gauges bungeed around your arm isn't much different than one and having a small light clipped to each of your shoulder straps in addition to the cannister light you would have anyway is also not noticeable.

I'm not saying it's needed but if one were to choose to dive that way all the time it wouldn't be a big change either would it?

I agree with your reassessment of what's important (high risk of occurrence and how much it matters if it does happen). However there is another factor. Is it easy to do and will it make a dive go smoother.

If you lose a mask (comes of and falls down a wall) your buddy will help you to the surface but if you had a mask you could continue the dive. In your particular case you've mentioned having problems with mid-water ascents. I've got to think that not having a mask has got to give you a similar feeling of lack of orientation.

Have a gauge go out. Not a big deal but with an extra gauge it's no deal at all and the dive continues. Maybe it's a long day trip or a two day weekend dive trip. I personally like knowing that my dives will rarely be called due to equipment issues. I've gotten in the water and had a computer flood. I've gotten wild readout's mid-dive. It's not a big deal either way but in my case the dive continued as usual.

If I had to carry two consoles or two huge lights or whatever then the risk/reward analysis would change but I don't have to do those things.

This isn't about what I would do but I'm trying to point out that redundancy at little cost/bother is also an option.