Should all recreational BCD’s have two tank bands?

[Soloist]

Immediately after receiving our OW cert we purchased new back inflate jackets. Both were configured with a single cam band. On numerous occasions Lisa’s aluminum 80 would gradually slip down or the plastic cam buckle would pop open during entry. Fortunately, even with my very limited diving skills at that time, we resolved the issue calmly at depth and continued our dives. Trying the many “remedies” to prevent this from happening resulted in only limited success. I considered adding secondary bands to our jackets, but discovered it was impossible. Then the day came when it finally happened to me. I hit the water for a negative entry night dive and all of a sudden my regulator violently fish-hooked my head to the right due to the full steel tank relentlessly trying to descend to bottom without me. Luckily, Lisa and the DM secured my tank within seconds, but I knew I never wanted to experience that again. I got my first BP/W shortly thereafter.

A lot of us have seen, if not experienced for ourselves, a tank slipping down from a BC. If not, keep an eye out for a diver with their tank hanging halfway down their butt clutching madly at their second stage like a starving peasant gnawing on a turkey leg. Now you have seen it and hopefully the diver will have the wherewithal to work with you to resolve their problem. This issue has been a reoccurring theme in the recent “have you ever had to doff and don your rig while diving” thread. I believe, like many others, this issue is preventable by incorporating dual tank bands. I eluded to the various remedies to alleviate tank slippage, but how many new divers are aware of these techniques? Some poodle and back inflate jackets have dual tank bands, but the vast majority of the mid/entry level and rental BC’s do not. The very BC’s most likely to be on the backs of new and unsuspecting divers.

Questions. Should all recreational BC’s going forward have two tank bands? This feature is standard on BP/W rigs. Is it possible for the diving community to influence BC manufacturers to include secondary tank bands to their upcoming designs? Adding this feature comes at a price, but doesn’t diver SAFETY outweigh the additional expense to the end user? Has the standard plastic cam band strap run it’s course as a single tank band solution and do we need an industry wide alternative? Some do exist, but they are considerably more expensive. Moreover, as a solo diver I like the belt and suspenders approach of dual tank bands and they are also very cost effective. At the very least, should that ineffective plastic sleeve found on most tank bands to supposedly grip the tank be replaced with an actual rubber compound pad? Is this even considered a problem by the majority or am I just howling at the moon?

 

[Blasto]

Well, there's the safety strap.

If you get one tank strap to slip or open, both might as well. It usually happens when they're very new, or when they've been threaded wrong. A correctly threaded, broken-in strap will not slip or open on its own. So the safety strap (thin one going around the valve), being different, might be offering as much protection at less weight and cost.

For most rec divers, it's an issue of extra stress on the hoses; the tank's still held up to the jacket by the inflator hose. Of course it can also happen to be a pull dump.

 

[tbone1004]

Most problems with single tank bands as far as slippage is concerned can be solved by pre-wetting the bands *nylon stretches quite a bit when wet* and appropriately tightening the bands.
The biggest issue with single cam bands is they create a fulcrum which can cause the rig to position itself a bit funny. That's what those top loops of bungees are good for to keep the top of the tank held forward.

DSS addresses it with a compression block in the spine of their bc's and have a gripping pad on the band which is good. Realistically though, I just pre-wet my straps, and make sure that after the first dive, I resnug them. Never had an issue...

 

[Colliam7]

Questions. Should all recreational BC’s going forward have two tank bands? . . . Is it possible for the diving community to influence BC manufacturers to include secondary tank bands to their upcoming designs? Adding this feature comes at a price, but doesn’t diver SAFETY outweigh the additional expense to the end user? Has the standard plastic cam band strap run it’s course as a single tank band solution and do we need an industry wide alternative? . . . Is this even considered a problem by the majority or am I just howling at the moon?

This is a series of questions that possibly could as easily be re-framed, as answered universally.

Should ALL recreational BCDs have it? Not necessarily. Maybe, the better question should be, 'Should a recreational diver buy a BCD with only one cam band, or should they buy a unit with two cam bands. I personally prefer dual cam band units (BP/Ws, for example). I strongly recommend to students and divers considering a gear purchase that whatever they buy should have two cam bands. But, I think manufacturers should be able to market units with one cam band.

Is it possible for the diving community to influence manufacturers? Sure. Vote with your dollars - just don't buy a single cam band unit. There are LOTS of BCDs on the market,. There are LOTS of great units with two cam bands. There is no pressing need to buy a unit one with only one cam band. So, there already exists an industry-wide alternative, for those who want it. My very first BCD was a Zeagle Ranger (a 2001 purchase) was a two-band unit. I wanted two bands, I bought two bands. I didn't consider a BCD without two bands

Does diver safety outweigh the potential expense to the end user? Well, I personally don't think it is a particular safety issue. A cylinder coming loose during a dive is a user issue. Yes, I have seen a number of divers in the water with a cylinder that was slipping down, and out of their cam band. I have never had a backgas cylinder come loose when I was diving a unit with only one cam band. But, I always wet the cam band before assembling my scuba unit. I also adjust the band so that I can just barely close the cam. Now, I do use a single band BCD (AquaLung Wave) in the pool because it is so inexpensive. It has one cam band. Still, the cylinder stays put.

I have had a plastic cam buckle fail (aka 'break'), during gear assembly, once in the past, when I was using a borrowed BCD. Lesson learned. Since that time, I only use stainless steel buckles. My preference.

Is there such a 'pervasive' problem with single band units? I really don't think so. But, I don't think you are the only one who expresses a preference for two-band units, or finds one-band units to be less than optimal.

My preference for two-band units has to do with stability, which tbone alluded to. The second band affords greater stability along my vertical midline. So, that is what I use.

 

[The Chairman]

I only use and let my students use BCDs with dual tank bands. Do I think we need a rule or law to that effect? No. I just know what works for me and mine.

 

[TMHeimer]

I only use and let my students use BCDs with dual tank bands. Do I think we need a rule or law to that effect? No. I just know what works for me and mine.

Agree. Either that $10 device you mentioned to me or my $100 Bio Tank Lock for single bands. No laws. I should mention that wetting my particular band didn't help slippage much. Maybe because it was an old BC.

 

[Jonny Wishbone]

I'll bet the strap band is threaded incorrectly. youtube is your friend here on this one. Plus when you put your BC on a tank, you gotta make it as tight as you can with the cam buckle open, then pull the cam over and make sure there is plenty of velcro to stick the end to. pick up the tank with your fingers under the buckle and the other hand on the top of the BC and give it a shake down to see if it slides. if it slides its obviously not tight enough. Like Tbone said,,wet it first...no mater how new or old it is..it does have the rubber sleeve on the band right?

 

[Damselfish]

Why take choice away, one tank band is not automatically bad, and 2 are not necessarily better. Certain designs (like anything with no/minimal hard pack) pretty much need 2 straps to be stable. Others may not. I will agree 2 straps can be more reliable, but sometimes that's because they do a good job of covering up for crappy straps, design or user error. On the flip side, 2 straps can make it hard to use tank holders on some boats, or at least I used to see that alot. They can also make it hard to adjust the height of the tank to where some of us need it to avoid hitting our heads on the reg if we want to ever look up. (I sometimes see people with 2 straps using only the lower one with the top one flapping in the breeze to get around this - better to have something intended for one strap than 2 you can't use one of. I have a Zeagle express tech and was able to creatively move the top strap lower adjacent to the lower strap or I would have that problem. Travel BCs with one real strap and one locator kind of strap don't really work well in that case either, because the tank position is more or less fixed unless you don't use the top strap, which is probably really needed for something soft and foldy. I tried the Zuma and that was a non-starter for me.)

My husband happens to use the AquaLung Wave that was mentioned, really simple jacket usually found in rental, it's what he likes. It has one strap. The original was crappy and a problem. He replaced it with an old Scubapro strap we had lying around, the ones with the metal buckle that are rock solid as long as wetted down first and adjusted properly. Much better.

 

[scubadada]

Sorry, but this thread is not representative of effective single band straps. I've dived Scubapro single band straps for about 1300 dives and have never had a loose cylinder. I have recently dived a similar Aqua Lung single band strap for about 200 dives and found the same result. Perhaps the straps that performed poorly, were an inferior design in the first place.

 

[hroark2112]

Why do we have to regulate everything? Buy what works best for you.

The last thing this sport needs is more "rules" for manufacturers in order to fix a user problem.