Double alum. 80s

[rhwestfall]

I do wonder how people survived before these courses came about??? It's a total mystery that so many older divers are still alive.

IIRC, it was called a "mentor".......

 

[HantsDiver]

I never took a single class to dive doubles. Seriously, it is not rocket surgery. You do NOT have to have a 7' hose simple because you are in doubles. The only RULE I would say to someone just wanting to dive doubles as a big ole stable lots of gas platform in recreational dives, ISOLATOR OPEN. Thats it. You actually have real redundancy with doubles and with very little work from the OP it is a much safer platform to dive. Band you up some AL80s and get on with it bud.

Shame on you. Encouraging such dangerous and risky behavior.

As you well know we should be encouraging people to support their local dir instructor or worst case their local dive shop (IF they dive exclusively with a twinset otherwise it's totally reckless).

Tbh I am fully in support of the way the diving industry is going. The other day I went to buy a new dsmb. At the shop I went to get my credit card out. Fortunately, the staff were on the ball and explained before that card they would need to see my smb speciality one. I'd left it at home so had to drive two hours to get it - but I totally respect them looking after me like this. If it went this way with twinsets it would be much safer and better.

This is evidence led. There have historically been a lot of people injured by using twinsets before they were ready and most importantly without the proper training. If they had been diving with a single tank it would never have happened.

 

[AJ]

The other day I went to buy a new dsmb. At the shop I went to get my credit card out. Fortunately, the staff were on the ball and explained before that card they would need to see my smb speciality one.

So handling an dsmb requires certification according to them? Who do they think they are? Scuba police?

This is evidence led. There have historically been a lot of people injured by using twinsets before they were ready and most importantly without the proper training. If they had been diving with a single tank it would never have happened.

It's probably not because of diving twinsets, but because the divers thought they could do dives they could'nt. Overestimating own skill level, not equipment choice per se is what gets people killed.

 

[Patoux01]

I would guess there's a sarchasm somewhere around... might need twins to dive that

 

[Doby45]

I would guess there's a sarchasm somewhere around... might need twins to dive that

I was thinkin the same thing..

 

[Jim Lapenta]

If you show up for my AOW class with doubles or sidemount you can bet that you'll do valve drills. Both of those are options for my AOW class. If during the pre-class interview and evaluation it's decided you need a little practice in the pool, valve/manifold shutdowns will be done.

It's stupid to dive doubles and not practice those as one of the first skills, since not doing them means you may lose twice as much gas as diving a single. You might have an extra 80 seconds or so if the SHTF but if you do a manifold close and valve shutdown you still have plenty of gas and no huge cloud of bubbles to deal with.

Heck, even in a single, when you go to the pony your required to carry you have the option of practicing a main tank shutdown.

 

[HantsDiver]

You say the same rubbish you are saying now about all courses and training, in the old days people took up the sport without any formal training or courses. Many got hurt that you don't know about and most of them survived one way or another. Heck, where I am right now, most people don't take formal agency sanctioned scuba courses and take up the sport and survive despite the many injuries that happen.

What I am saying is beyond rubbish, pure crap!

Stop being silly. There is no such thing as "formal agency sanctioned scuba courses"! What we actually have is good and bad diver training. Both of which gives us cheapo plastic cards which make people like yourself feel very important. Now there is nothing wrong with this. I've got over an inch of these plastic cards - I just have enough going on between my ears to realize that they don't mean anything.

For what it's worth I am very pleased that I did my equipment specialist course. It means I can now wash my bcd knowing I'm doing it in the safe and proper way. I personally plan on doing the dive against debris specialty course soon so I can safely spend my time litter picking in the water properly in my spare time.

I still won't have done any specialy twinset training though. I just got one and used it. I'm very fortunate that I didn't die or get injured like the countless others. I'll stick it on ebay (but only sell to certifed twinset divers) and go back to my single tank setup as it's much safer. Actually I do have a card that says twinset on it - I'm just grateful that I made it long enough to get that card. As an older man now I don't take as many risks.

 

[Patoux01]

It's stupid to dive doubles and not practice those as one of the first skills, since not doing them means you may lose twice as much gas as diving a single. You might have an extra 80 seconds or so if the SHTF but if you do a manifold close and valve shutdown you still have plenty of gas and no huge cloud of bubbles to deal with.

Sure, it's benefitial to master it. It's not detrimental to not master it, it just makes you dive a big single tank.

 

[Storker]

It's not detrimental to not master it, it just makes you dive a big single tank.

This.

In my diving community, I'd guess doubles are used by some 30-50% of the divers. Most of them have no technical training whatsoever, and they use their twinsets as a large single. There are a few advantages to using rec doubles, and keeping the weight closer to your COG is perhaps the one most commonly quoted. Another advantage s the extra capacity (I live in drysuit country, and generally gas consumption is somewhat higher in a drysuit than in a light wetsuit). The normal single around here is 10L 300 bar, or 12L 232 bar, IOW roughly 100 cuf in Imperial units. Typical rec twinsets are D7L 300 bar, or D8.5L 232 bar, IOW somewhere around 150 cuf in Imperial units. If you have gills, it's more than enough to take you into deco, but if you're a hoover in a drysuit, it's just the little extra that won't make you the guy who's cutting the dive short due to gas limits.

That said, from my limited experience a double Al80 set is neither fowl nor fish, to use an expression from my language. It's too large to give a nice, compact setup close to your back, and it's really a bit small compared to the standard tech twinsets I've seen (typically D12L 232 bar, or around 200 cuf). If I were to go for a rec twinset, it'd be smaller, and if I were going the tech route it'd be larger.

 

[Lorenzoid]

I took a Doubles class, but part of what I wanted to gain from the class was knowing what tanks to select for my needs. If you know you want double Al 80s, which I understand is a pretty common configuration for wetsuit diving in warm water, then that's not an issue. Like most aspects of recreational diving, I wouldn't classify it as "rocket science," but there is stuff you need to know, stuff that's good to know, and stuff that's a bonus to know. You can learn it from a class, a mentor, or if you're the kind of person who doesn't fret about being unsure whether he's covered all the bases, from random people and videos on the Internet. The class was good for me, because I wasn't really sure what there was to know about doubles, and now I'm satisfied that whatever there is to know--and then some--was covered in my class.