Dives With Twin Tanks

[JimSiam]

I want to try diving with twin tanks, are there any shops that offer this in Pattaya that anyone recommends that can offer this on day trips?

[Shurup]

I dont think you will have any luck with trying it in Thailand. I've never seen anyone doing it anywhere here and honestly IMHO there is nothing in Thailand that requires dual tanks.

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[bazmlb]

Adventure divers on Jomtien 2nd rd are able to do this for you and have all the gear and a nice boat too, there are a lot of wrecks in the gulf that are in deeper waters such as the Legarto at 75 meters (http://thaiwreckdiver.com/lagarto.htm) there are also a lot of freshwater caves in Thailand that twins are useful for.

[Shurup]

75 meters is beyond a rec diving isn't it? I was assuming the OP isn't a tech diver.

Didn't know there are freshwater caves here, where would I get more info on this?

[bazmlb]

75 meters is beyond a rec diving isn't it? I was assuming the OP isn't a tech diver.

Didn't know there are freshwater caves here, where would I get more info on this?

75m is beyond rec diving, but most people looking to go to twins are usually progressing to that level, it's hard to start doing the tech stuff and mucking around with bouyancy of twins all at the same time, so if you knock off that part first there is less things to deal with in the water at the tech stage.

Bruce Konefe is the most knowledgable here on the subject and has website about it here http://www.deeptecthailand.com

Here is a video from Khao Sak National Park

[Shurup]

That was my point in my 1st reply, should have been more speciefic... I thought and still think he's a rec diver (and perhaps a newb if he's asking this) and unless here in Thailand are cave systems similar to those in Mexico there is no need for dual tanks for any other rec diving activity.

[ScubaBuddha]

Don't know if your going to find duals in Thailand. I've only seen tech divers use them. These days you can get you can get a single 130cft/680litre tank that has more capacity than a lot of traditional recreational dual systems.

For tech diving and info on fresh water diving in Thailand the best guy is Ben Renemants at Blue Label Diving. http://benreymenants.com/thailand/

[JimSiam]

That was my point in my 1st reply, should have been more speciefic... I thought and still think he's a rec diver (and perhaps a newb if he's asking this) and unless here in Thailand are cave systems similar to those in Mexico there is no need for dual tanks for any other rec diving activity.

That was my point in my 1st reply, should have been more speciefic... I thought and still think he's a rec diver (and perhaps a newb if he's asking this) and unless here in Thailand are cave systems similar to those in Mexico there is no need for dual tanks for any other rec diving activity.

I wanted to get use to them here as I am planning a Holiday to Truk Lagoon to do some diving there on the wrecks and want to do some dives that will be past rec bottom times so will need to get into deco certifications as well, preferably TDI stream, I will check out Adventure divers and let you know how i go.

[rod2011]

In Pattaya you have Aquanauts dive centre in Soi 6 as well as Mermaids dive centre in Jomtien.

Both of these centres will help you out and supply twinset cylinders (doubles).

[h90]

75 meters is beyond a rec diving isn't it? I was assuming the OP isn't a tech diver.

Didn't know there are freshwater caves here, where would I get more info on this?

75m is beyond rec diving, but most people looking to go to twins are usually progressing to that level, it's hard to start doing the tech stuff and mucking around with bouyancy of twins all at the same time, so if you knock off that part first there is less things to deal with in the water at the tech stage.

Bruce Konefe is the most knowledgable here on the subject and has website about it here http://www.deeptecthailand.com

Here is a video from Khao Sak National Park

Also it can be stretched what rec diving is. I dove the Francesca di Rimini in Croatia: 47 Meter with deco, which is (or was) rec diving with CMAS.

PADI trained DM are of course shocked by that idea...

They dive this with 15 Liter Mono, but Doubles would be a good idea.

[stevenl]

Also it can be stretched what rec diving is. I dove the Francesca di Rimini in Croatia: 47 Meter with deco, which is (or was) rec diving with CMAS.

PADI trained DM are of course shocked by that idea...

They dive this with 15 Liter Mono, but Doubles would be a good idea.

PADI calls that Tec Rec, up to 50 meters, and with twins plus sidemounts as well.

[h90]

Also it can be stretched what rec diving is. I dove the Francesca di Rimini in Croatia: 47 Meter with deco, which is (or was) rec diving with CMAS.

PADI trained DM are of course shocked by that idea...

They dive this with 15 Liter Mono, but Doubles would be a good idea.

PADI calls that Tec Rec, up to 50 meters, and with twins plus sidemounts as well.

yes PADI does, I think CMAS does not. Anyhow before PADI got that dominant it was common to go deeper or do some deco. Of course that time scuba diving wasn't such a mass sport. PADI is just a company. As private person you can do what you want (at least in Thailand). Only for dive center it may cause troubles with the insurance. So if someone goes deeper than 40 meter, doubles make sense. I have a 15 liter 300 bar tank for it. But it is such a heavy thing that I didn't use it yet. Taking it from the house to the car almost kills me.....

[LucidLucifer]

I've never seen anyone doing it anywhere here and honestly IMHO there is nothing in Thailand that requires dual tanks.

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IMHO anything less than twins, or at minimum carying a pony cylinder, for anything but shallow reef dives, is playing a dangerous game.

[Shurup]

I've never seen anyone doing it anywhere here and honestly IMHO there is nothing in Thailand that requires dual tanks.

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IMHO anything less than twins, or at minimum carying a pony cylinder, for anything but shallow reef dives, is playing a dangerous game.

At 30-40 meters depth, your bottom time would be pretty close to how long a single tank will last you.

What dangerous game are you talking about?

Running out of air? - Watch your gauge and don't dive alone.

Developing a sudden leak? - Twins won't help here as they're bridged.

What else?

[h90]

I've never seen anyone doing it anywhere here and honestly IMHO there is nothing in Thailand that requires dual tanks.

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IMHO anything less than twins, or at minimum carying a pony cylinder, for anything but shallow reef dives, is playing a dangerous game.

At 30-40 meters depth, your bottom time would be pretty close to how long a single tank will last you.

What dangerous game are you talking about?

Running out of air? - Watch your gauge and don't dive alone.

Developing a sudden leak? - Twins won't help here as they're bridged.

What else?

Usually you can close the bridge and loose only one tanks air

[LucidLucifer]

True, but have you never heard of deco? Even without planned deco, more air than you need is never a bad thing. How about this scenario: You're on a 35m dive, nearing the end of your bottom time. Going by the rule of thirds you and your buddy have 80 bar left in your standard ali 12 that you generally see out here i.e. 960 litres left. For whatever reason suddenly you're out of air. Assuming a SAC of 20 litres per minute, and that in said situation both you and your buddy's SAC doubles, you're are now getting through 80 litres per minute. At 35m you take a minute to get sorted, settle yourselves and start your ascent....except that now you've just used 360 litres of air in that minute.....now have 600 litres left to share.

You expedite your ascent while keeping it within accepted margins, 18m per minute....call that 270 litres used. You are now at 17m with 330 litres left.....or less than 3 minutes before you're out.....presuming good practice dictates you do a safety stop, wouldn't you agree that you're cutting things mightely fine?

Watching your gauges is a given, you shouldn't run out through failure to do so, but it does happen.

Don't dive alone....great advice, drag your buddy into the sh*t when you could have done a simple switch onto your backup. When you dive with the a large proportion of recreational 'holiday' divers, you're effectively diving solo. Any unknown buddy is an unknown quantity. Expect them to come to your rescue at your peril. Will they for one? are their skills upto it for another?

Developing a sudden leak, I presume you mean either a blown first stage or a freeflowing second stage, rather than a need to pee in your wetsuit.

Twins will help; with singles.....oh dear....big problem. Independent twins, switch regs onto the other cylinder.....no problem. Manifolded twins, shut down the manifold to isolate the leak, job done. I'm safe, my buddy is safe.

Edited April 9, 2012 by LucidLucifer

[Shurup]

Well you make it look really gloom.

I couldn't imagine what would you do for a whole minute at 35 m before ascent? If it's obnly me and a buddy, I would be sucking his air and be on our way up in seconds. If you're in a larger group - so is better, more people to share the air with so nobody runs out, but it may take a min to let everyone know that the dive is over. Recreational 'holiday' divers still need to have and remember their training to go to that depth, also don't forget pre-dive breefings.

I agree that nobody should skimp on their safety, but this is clearly an overkill, never saw anyone doing that on any of my deep dives.

If you feel better, you could brobably request to take a spare one with you if it makes you feel safer.

[LucidLucifer]

It's not a case of making things look gloomy. It's a case of being prepared for the worst case scenario, that is what proper dive planning is.

As for the minute, you'd be surprised how long it may take at that kind of depth to get yourself settled before starting an ascent. For the extra few moments it takes to do it, makes sure you and your buddy both ready to start a controlled ascent, get your breathing under control after what would be, let's face it, a pretty scary few moments, that time could be well spent. I'm not suggesting hanging around admiring the scenary, more a lets get control of what's happening rather than a 'give me you AS and we're off up' ...that just increases the risk of things going further wrong with a rapid ascent. For arguments sake, lets say it takes 20 seconds, still you and your buddy are in shitty predicament.

Anyway, my main point is, none of this would be a problem if you were self-sufficient in the first place. To say it is clearly overkill just highlights an obvious flaw in certain training agencies practises.

Tell me, if on a night dive, do you carry a spare torch....of course you do! Do you shove a spare mask in your pocket? It's good practice......loosing a mask can be a big problem if you haven't a spare, just the inconvenience of spending a bit of cash on a new one if you have a spare with you!

Funny how people are trained to put a spare torch in there kitbag, but not a redundent air supply, the most important thing!

Edited April 9, 2012 by LucidLucifer

[Shurup]

We can agree and disagree on many points... I will not discuss this any firther, we have different opinions.

I have nothing against spare equipment and was actually thinking about buying spareair kit, it can almost fit in your BCD pocket. You should get one if you're worrying.

[LucidLucifer]

I think it's fair to say we agree to disagree. Each to their own, and diving is all about being comfortable with your own kit, its configuration and what you're doing (will most likely get some DIR dude telling me that that is DIW) upto them.

I'd do your research before investing in a 'spare air' especially if you're doing deeper dives. But a 'spare air' is better than a 'no air' any day of the week!

Happy and safe diving.....

[h90]

Well you make it look really gloom.

I couldn't imagine what would you do for a whole minute at 35 m before ascent? If it's obnly me and a buddy, I would be sucking his air and be on our way up in seconds. If you're in a larger group - so is better, more people to share the air with so nobody runs out, but it may take a min to let everyone know that the dive is over. Recreational 'holiday' divers still need to have and remember their training to go to that depth, also don't forget pre-dive breefings.

I agree that nobody should skimp on their safety, but this is clearly an overkill, never saw anyone doing that on any of my deep dives.

If you feel better, you could brobably request to take a spare one with you if it makes you feel safer.

His very improbable calculation still gives a rest of 30 bar at 17 meter.....

[LucidLucifer]

Okay, you have just enough.....cutting things close though, which is exactly what we'e taught not to do, supposedly!

Just say you and your buddy are two seriously ice cool dudes or dudettes, and your breathing rate is normalised back to 20 litres per minute when you hit 17m. Still only gives you and your buddy 3 mins before you're out. So of course, you continue your ascent....nobodys going to want to hang around, and you do the last 12m to your stop in 1 minute, call that 80 bar used. Now you have approx 250 bar. You've made it!!!! you do three minutes at 5m and surface with roughly 70 bar in your cylinder, your buddy can now inflate his jacket, holding you up while you orally inflate yours, and you're saved.

Except....In this best case scenario:

1) we're presuming breathing normalises by 17m

2) we're presuming neither of you panic and that you control your ascent to within excepted margins

3) we're presuming that you manage to hold your stop at 5m, and that stop is long enough after a 35m dive, and after ascending 30m in two minutes......i see a decompression incident waiting to happen.....

4) we're presuming you make it to your buddy in the first place and they have the skill and composure to help you.

A lot of 'ifs' here......

I am genuinely interested in how you think that my calculations are improbable. They are 'worst case,' but only a fool would calculate things on best case. In many ways, my presumption of a SAC of 20 litres is quite generous. I sup a lot less than that, there of plenty of divers that sup alot more.

I think this is an important debate that we all, as divers that like to end the day back on the boat rather than in the hospital/hyperbaric chamber/morgue, should be interested in.

I am happy to be corrected.

Edited April 10, 2012 by LucidLucifer

[h90]

Okay, you have just enough.....cutting things close though, which is exactly what we'e taught not to do, supposedly!

Just say you and your buddy are two seriously ice cool dudes or dudettes, and your breathing rate is normalised back to 20 litres per minute when you hit 17m. Still only gives you and your buddy 3 mins before you're out. So of course, you continue your ascent....nobodys going to want to hang around, and you do the last 12m to your stop in 1 minute, call that 80 bar used. Now you have approx 250 bar. You've made it!!!! you do three minutes at 5m and surface with roughly 70 bar in your cylinder, your buddy can now inflate his jacket, holding you up while you orally inflate yours, and you're saved.

Except....In this best case scenario:

1) we're presuming breathing normalises by 17m

2) we're presuming neither of you panic and that you control your ascent to within excepted margins

3) we're presuming that you manage to hold your stop at 5m, and that stop is long enough after a 35m dive, and after ascending 30m in two minutes......i see a decompression incident waiting to happen.....

4) we're presuming you make it to your buddy in the first place and they have the skill and composure to help you.

A lot of 'ifs' here......

I am genuinely interested in how you think that my calculations are improbable. They are 'worst case,' but only a fool would calculate things on best case. In many ways, my presumption of a SAC of 20 litres is quite generous. I sup a lot less than that, there of plenty of divers that sup alot more.

I think this is an important debate that we all, as divers that like to end the day back on the boat rather than in the hospital/hyperbaric chamber/morgue, should be interested in.

I am happy to be corrected.

At 3), we are speaking about a non-deco dive, stop at 5 Meter is nice but not necessary. If there is not enough air, skip it.

[LucidLucifer]

Agreed, not totally necessary, but prudent....i'd refer you to #3 too, rapid ascent from 35m, decompression incident waiting to happen.

It all leads to this......

[h90]

Agreed, not totally necessary, but prudent....i'd refer you to #3 too, rapid ascent from 35m, decompression incident waiting to happen.

It all leads to this......

Therefor PADI did rightly limit the max. deep for Open Water with 18 meter.

The problem is that the deep dive "course" for 30 meter doesn't really teach much/doesn't really prepare for accidents under water.

The deep diver is also not much.....

When I think someone makes the courses in Pattaya with an uninterested Pattaya Instructor and than goes with his buddy on in some remote area with faulty equipment (pressure gauge shows wrong, exhaust valve on the Octopus broken (both common) to 40 meter (maybe 1 year after the last dive) than it is scary.

On the other side a diver from a scuba club in Germany, where they refresh all the skills all the time in cold water. Shouldn't have any problems.

I think it is less a question of the equipment than of the brain. I think PADI speaks a 1000 times of the personal limits.

[LucidLucifer]

You're probably right about that, PADI did do the right thing by limiting the depth. I also totally agree that the 'deep dive' course doesn't really teach you much. I'm not going to critisise the fundamentals of PADI course content, they do teach you the right thing. My critisism of them would be that information and skill development is always held back......until of course you pay for the next speciality or diver grade. Inherently risky, but it's a commercial operation so you can expect nothing more.

I think with your above comments we have almost come full circle, back to my original post. I have said throughout that you are relying on your buddy to help you out of the situation. Unless you dive regularly with them, and you know they are confident and competent, you are placing your life (and theirs) at risk.

Give me the above-mentioned German club diver and I'd feel more secure, but I wouldn't rely on them. I'd hope they'd help me, as I would help any buddy I dive with....but is it a guarenteed?....the answer is no.

Going back to the incident pit I posted above, and the above scenario (extreme I know, but nevertheless possible). You really are cutting things fine, and relying on fortune. Diving on twins, say this was to happen to me, what would happen?

I'd go opps, lost my x, y or z here, better go to my redundent.....no panic, just a simple, well practised regulator switch (I dive independents). Signal my buddy that the dive has ended, got a little problem, nothing to get worked up about...no panic. Start a slow ascent at a leasurely 9m per min to about 20m, pop up my dsmb, reel in slowly giving myself and my buddy plenty of time to gas off....no panic. Maybe do a deep stop at 12 for a minute or so, then reel in to 5m, another stop, then surface, inflate my bcd from back gas....no panic. Me and my buddy are safe, calm and back on the boat in no time.

Your point about personal limits is a great one, I agree totally. I dive to my own personal limits, but do I know if the unknown buddy is? Human nature, the euphoria of being on holiday/the environment, says they will often push those limits, IF they even know what their limits are. Personally, I don't give a shit, unless I'm operating in instructor and/or dive leader mode. I can and will help any diver in distress, but if it were to happen to me, i'd rather help myself in the first instance.

[h90]

I complete agree! In general: I really don't like what and how PADI teaches. To many rules and dogmas. But I must agree that it might be the best and safest way to do it.

But specific on the deep dives PADI is taking it surprisingly easy. I think 40 meter is too deep for that little training. But on the other hand they deny that it is even possible to go deeper than 40 meter or make some deco dives.

On one side allowing 40 meter for every moron and on the other side be complete restricted for anything more. That seems not balanced.

That personal limit thing seems not to work for everyone.....Evolution at work....

[LucidLucifer]

I agree H90, If you want to look at partial pressures, a 55m dive on air is safe, although PADI might make you believe something different. I'm certified to 55m but i'm no techy. What I am is regular diver that has practiced and honed his skills.

Edited April 10, 2012 by LucidLucifer

[h90]

I agree H90, If you want to look at partial pressures, a 55m dive on air is safe, although PADI might make you believe something different. I'm certified to 55m but i'm no techy. What I am is regular diver that has practiced and honed his skills.

Where did you certify for 55 meter? I somehow understand what PADI thinks......When it goes deeper than 40 meter, you need a real planning on the air, on the time and be serious about it. While all the PADI think is based on "fun". That doesn't fit together. And all that "from Zero to Hero" Dive Master and Instructor (they offer these courses in Pattaya) believe PADI like it is a religion. And of course it is an insurance thing for the Dive Centers.

[LucidLucifer]

Certified in the UK.