Why no redundancy in mainstream rec scuba?

[2airishuman]

Aren't most deaths in scuba diving caused by an out of air situation ?

It very much depends upon how the data is interpreted.

The received wisdom is that approximately half of scuba diving deaths have medical difficulties as their primary cause, with heart attacks, strokes, asthma, epilepsy, and complications of diabetes being the most frequent conditions to blame. But even this figure is not without controversy, because contaminated gas may have been the root cause in some cases, and some cases may have been misdiagnosed or misreported.

Simple out-of-air events occur far more frequently than fatalities. Most divemasters witness multiple out-of-air events during a lifetime of diving. I am unaware of useful statistics, but I believe that the situation of someone unexpectedly running out of air at depth probably occurs at least 10 times as often as out-of-air fatalities -- perhaps as much as 100 times as often.

The ones that result in fatalities almost always involve multiple other problems occurring concurrently, among them excessive weighting, poor visibility, extreme inexperience, inability to achieve and maintain buoyancy at the surface, separation from surface support.

 

[dmaziuk]

Interesting try. So following your train of thoughts a spare second stage is superfluous too as is a BCD.

Also the main second stage, the first stage, and the cylinder: I don't carry any of those when I freedive as they are indeed superfluous to the dive.

 

[northernone]

Bring what is needed on a dive. You mentioned a compass. If the conditions require it, carry it. If you're skilled to use it, carry it. If you like something, carry it.

I find a trend to substitute extra equipment for lacking skill in order to feel safer is frightening.

I'm certain complete spare equipment, including wetsuit repair kit, extra fins, along with me would make it more comfortable when something goes wrong, as long as I have the skills to use them. That isn't a matter of safety for the vast majority of divers.

The fact something will be useful eventually doesn't justify carrying it from a safety perspective. There's a point where redundancy results in unnecessary complexity and will actually contribute to more deaths.

Can I need a spare mask in a 10ft deep dive? Yes. Is it an item for improved safety? Only perhaps.

I can safely come up from 130 without a mask. Added a second mask doesn’t make me safer. It's an extra item to entangle, think about and deploying would keep me at depth longer than simply aborting the dive.

Having the mindset of fixing problems underwater without the skills to back up this practice is dangerous.

All in all I think the amount of gear is need to be reduced to the amount the diver can successfully use in a stressful situation.

This is a little rambly. My apologies.
Cameron

 

[KevinNM]

Aren't most deaths in scuba diving caused by an out of air situation ?

In the vast majority of cases the culminating event in a fatality is they drown. Often they have no gas left at that point, but not always. What the chain of events that led to that is very varied.

 

[reefrat]

I regard every dive as a solo dive as far as my personal safety is concerned, because in practical terms with most “buddies” that is exactly what it is. My safety is My responsibility!

Having redundancy of essential equipment, and keeping up the necessary skills in finding/using it allows me to have a peace of mind that I can deal with any foreseeable situation “down there” without breaking a sweat, and as far as I’m concerned that’s the way it should be.
Ive been diving since the early 70’s and remember well the minimalistic approach we had then- “J” valves included. The training I completed as a teenager bordered on militaristic with giant strides from 20 ft and multiple equipment free ascent scenarios then dive back down to re-don on every session. I wouldn’t say that is particularly fun or even safe, but it was confidence inspiring for the types of dives we typically did back then with an average depth of maybe 40 to 60 ft.

I understand the resistance by many these days to what they may see as increasing the complexity of training and equipment required for rec dives! But the reality is that these “rec” dives that I see conducted around the Caribbean and there-about are routinely at depths of 100 ft plus (often 120 ft plus) with an almost alpinist approach to equipment and divers who have minimal experience (IMO) who have certainly never practiced equipment failure drills at these depths, or maybe ever since their OW or AOW course.
The inherent reliability of modern scuba gear, in particular regulators, has lead to a level of complacency- naaaah, it’ll never happen! And maybe it won’t, if your lucky. But it only has to happen once and most people are simply not prepared for a first stage failure, blocked K valve tube, LP hose blow out, inflator hose free flow, sudden mask lens implosion, entanglement, panicked buddy grabbing everything etc.

I have seen or been first hand involved in all of these scenarios and do not believe that most of the typical rec divers are equipped in equipment or skills to deal with them safely. The redundant equipment I referred to in the OP was mainly a spare mask and gas supply/regulator and I don’t believe I will see any argument to sway me that these are not necessary.

 

[CT-Rich]

I have never lost a mask on a dive (my daughter did throw one at a seagull she thought was choking on a sock). I essential safety gear is a signal whistle, a DSMB, a light (it stays in the DSMB pocket), ditchable weight (this could be considered redundant buoyancy), two cutting tools (BCD knife and a line cutter). Snorkels are along if there is the possibility of a long surface swim. I have a pony bottle for solo, but I won't bring it most of the time because most of my solo diving is less than 35' ( this will bring a great deal of consternation I am sure). Even a catastrophic failure, like an O-ring will still allow a safe ascent. I gas plan pretty conservatively when I am by my self because I know I may want that extra margin of error. I plan my gas conservatively when I am with someone else because I don't want to embarrass myself by needing their gas. If you get in the water not knowing whether you have air in your tank and it is turned on, you should really look for another sport. Diving alone is something I enjoy immensely, but failures in planning and judgement are entirely my own, but

 

[Steve_C]

Typical rec diving is 80-100+ feet. Possibly limited viz. There is no DM or guide in the water. Often you have an instabuddy who may or may not be reliable and you may have met on the boat. Often some current at least top side. There are likely no other boats for miles. You are 20-30 miles offshore. Life is simple if you go back up the anchor line. It becomes more complicated and dangerous if you are doing an open water CESA. I think I am a pretty good buddy. I do not feel it is safe to depend on most buddies and do not do so. So in the ocean I am always in a solo configuration. I have shoulder mobility issues so I have things where I can reach them. I really do not care what others think. I dive relaxed and happy.

If I am not in NC and doing easy reef dives the situation is different. I do not bring a pony. Do usually have an SMB and reel since may also do some drift dives. Carry two knives. One readily available one safe in a pocket. Have had to use them a couple times.

 

[shurite7]

Your buddy is your redundancy. While the extra gear may seem like a good idea, the best piece of gear is ones ability to think. Situational awareness, keeping up on skills and knowledge are far better than carrying the extra gear. Think about it, even if one is taught how to use all the extra gear will that person keep up on the skills to handle all the extra redundancy? Most likely divers will not.

Furthermore, DAN has noted that equipment failure is very very low. Failing to use the equipment properly is a problem DAN has noted. Adding additional redundancy will add to the number of issues with equipment.

Running out of air is a significant issue. While carrying a pony bottle seems great, one can ask if it isn’t a solution to a problem that doesn’t exist. Use your buddy for a redundant air source. More importantly, people should learn how to manage their air. This is something that isn’t intuitive for some people, yet it is something that is so simple.

Spare mask: the only reason I carry one is because people have broken mine before getting into the water by falling into me or while I am helping them gear up. The majority of the time I end up giving my spare mask to someone who doesn’t have a spare mask strap.

Compass: I always carry one when diving in lakes, especially a murky one. In clear warm water it really isn’t needed if one simply pays attention to their navigation. More accurately, maintaining situational awareness and mindfulness as to where the exit/boat is.

Smb/spool: not a bad idea for ocean diving, especially if diving from a boat. Here in MT, I’ve learned not to use an SMB or dive flag because it attracts boaters. One day a boater jerked my lift bag out of my hands when I was at a deco stop. Boaters always pull up to the flag because they do not know what it means.

Pony bottle: In Royal City, WA there is a fun dive which one can do inside an old missile silo. Pony bottles used to be required by the guy who let people in. What he discovered was the vast majority of people do not know how to use one. Twice he witnessed issues where the diver didn’t use the pony or used it incorrectly, even after being briefed how to use it before the dive. When I see people carrying a pony bottle I ask them how often they practice with it. The most common response I get is “never” because they “do not want to waste the air inside and pay for an air fill”. The others just stare with glazy eyes mystified that such a question could be asked.

The point is, divers who do not want to improve, maintain, and practice their skills will be no better off while carrying all of the additional “redundant” equipment. In my view, they will be more of a hazard. Again, using one’s brain is a much better option. I always tell my students and DM candidates to “be a thinking diving”, not a “just do diver.” Maintain situational awareness, adhere to mindfulness, practice their skills and keep up on their knowledge will make a person a much better diver.

 

[tursiops]

please elaborate

Others have made my point nicely.
Compass? No, not essential on all dives. Navigation? Yes, maybe it is essential, but natural navigation is perhaps even more useful than a compass....depends on the dive. Think shore dives on Bonaire's west coast.
DSMB? No, not essential on all dives. Signalling device? Yes, maybe it is essential, but at dusk/night I'll take a light over a DSMB...depends on the dive.
So, I've elaborated, but I doubt your question was really serious anyway!

 

[tbone1004]

Others have made my point nicely.
Compass? No, not essential on all dives. Navigation? Yes, maybe it is essential, but natural navigation is perhaps even more useful than a compass....depends on the dive. Think shore dives on Bonaire's west coast.
DSMB? No, not essential on all dives. Signalling device? Yes, maybe it is essential, but at dusk/night I'll take a light over a DSMB...depends on the dive.
So, I've elaborated, but I doubt your question was really serious anyway!

was mostly serious.
Even when using nat-nav which is in fact more useful in general, having a compass to get your relative bearing instead of using left/right I find very advantageous. Part of our basic OWT navigation course includes such a situation where the bearing has to be verified before taking on the nat-nav section otherwise they end up going the wrong way.

DSMB at night I still take since I can use it for redundant depth since I don't take redundant computers though I will say that a strobe is certainly more useful for being found at night.