What would you do?

[geoff w]

Lots of interesting and thought provoking answers. Tufi is very much a tourist dive resort catering to recreational divers, so I'm sure it's a group dive with everyone following the same exact profile

Get the training. That the resort has done this before with plenty of staged tanks is meaningless as far as you are concerned if you don't personally know how to plan the dives yourself. They don't know your personal limits that you have determined through training and experience for yourself. And if they are letting someone do these kind of dives on an al80 with tanks staged along the way I'd run the hell away from them. An al80 is not a suitable tank for a 45 m dive. Period. And if you can't make a tank last that long then your dive is not 100 minutes. Unless it's at 30 feet. Your dive lasts until you reach the turn pressure on your tank. You don't go extending bottom times with staged tanks that you have not been trained to use. Using stages tanks even for relatively shallow dives can throw you into deco. Deco that you do not know how to plan and how to do. You don't let someone else plan your decompression dives. Frankly you don't let someone else plan any of your dives at all.

I don't understand this argument. If there is a standard preset dive profile and the dive operator has additional tanks staged at the deco stops for divers, why does making a single Al80 last the full 100 minutes matter? How is this functionally different than doubles / multiple tanks, other than it makes it possible for the resort to offer deeper wreck dives to non-tech certified divers? I'm not sure about the comment of reaching turn pressure. We're talking guided dives. I've done plenty of local wrecks in the 100-125 ft range, and my turn point is always based on NDL and never on getting anywhere close to tank pressure

Get the training before you go. Plan your dive based off gas availability(your gas, not prestaged tanks from the Operator, and take her up on the offer. Don't ever blindly run a deco profile without knowing the logistics involved, and definitely don't dive deco on a single AL 80...

I don't think I've ever been to a tourist dive resort where anything other than single Al80s were available, and seriously doubt any could support doubles. Would you trust a tourist dive resort such as this with anything more complicated than a single Al80?

This sounds like old school air only deco, no O2, no gas changes, you just need enough air. Having done it many times in the past I wouldn't hesitate to do it again.

That is exactly correct. From friends who dived the Coolidge in Vanuatu, it sounds like common practice for dive operators to have additional tanks hanging for deco stops for those who need more air to complete their deco obligation than what an Al80 provides

135 is not optimal for Nitrox anyway. If you want a PO2 no higher than 1.4 you would need 27%. At 1.3 you are down to only 25% vs air at 21%. No big improvement.

Personally I would do mostly the shallower stuff. The deep dive sounds like a major trust me dive probably while narced. Not one I would do with an instabuddy or a guide hustling me along faster (or slower) than I want to go. Now if they let me rent a pony and hire a private DM so that I had a hopefully reliable buddy I would add in a deeper dive or two.

But then I am not a fan of being seriously narced when rationality is a survival asset and like more bottom time. So I tend to not dive deeper than about 105 most of the time.

If that 135 is sort of a resort rule and in fact the deep dives can be done around 100-105 then that changes things for me a bit but I would still want the pony and the DM.

---------added after seeing above-------

I should comment I can do 100 ft, safety stops, and be back on the boat using an AL80. Done it several times. The pony is reserve and not to get me to the boat on a normal dive.

Nitrox discussion is moot here because the resort doesn't offer it. I don't know about you, but hiring a private DM doesn't guarantee anyone competent. I've dived plenty of nice tropical places in the Pacific where local DMs are complete bozos. There's probably a better likelihood of a qualified diver in the group than just being alone with a DM

I do plenty of wreck dives locally in the 100-125 range on a single 80 tank and come back with plenty of air, on a conservative profile. 100 ft vs. 140 ft dive is still another almost 1.5 atmosphere, so air consumption relative to shallower depths increases accordingly

There is no mention on availability of nitrox(for deco) so I will do a "bounce dive" on those deep wrecks. Another tank would be very handy...

Nitrox not offered at Tufi according to their web site

Sounds like you are planning to get into technical diving, however briefly. If you make a habit of deep diving in areas where only AL80's are available, you might look into side-mount. Just a thought; lets you take 2 tanks with 2 reg.s (giving you redundancy) without bands or a manifold (unlike doubles).

If I were you, I think the question I'd ask is what course would be best to fairly quickly gain the knowledge I needed to competently do this deco. dive. In fact, if you can get the details of their dive plan, you can then run V Planner or what-have-you and see whether it's a plan you agree with.

And one potential nasty surprise; even diving their customary profile, I wonder how your dive computer is going to react? Any chance the deco. they do won't satisfy your computer? If not, will it lock you out? Should you run it in gauge mode rather than regular mode? Does yours have gauge mode? ...

Excellent suggestion on getting details of their dive plan in advance and running against V Planner or similar

Suunto Vyper computer, about the most conservative thing you can get. Yes, it does do gauge mode, but for a dive vacation with 3 dives a day for a week, that pretty much renders the computer useless for all remaining diving

Greetings geoff and you find yourself where we all were at one time or another.
I was in the same spot and it took a while and I dove dives I was certed for and comfortable with for as long as it took to secure gear / training.
Do I have any regrets? NONE
I took a year to get my gear in order then secured a excellent Adv. Nitrox / Deco. instructor.

What I found was that I enjoyed diving with my redundant rig on less demanding dives to.
I was on a few occasions felt a bit like I was crawling along while collecting my gear and learning to dive it.
It was a great year of learning, training, understanding the mind set of what deeper longer dives entail.
TAKE YOUR TIME, TRAIN WELL, SEEK OUT OTHER DIVERS WITH A HEALTHY RESPECT FOR DIVE PLANNING.

This is only my opinion enjoy diving where you are at right now.
Seek out training, gear, mastery of skills before taking on deco dives.
The devil is in the details and at depth is a bad place to be made aware of a failure you have not been prepared for.
Decompression is not an exact science there is a level of risk even trained, experienced deco divers accept you can get bent even when you do everything right! TRUE NOT MAKING THIS UP!
The farther down the rabbit whole you go friends start getting hurt, "Bent that is" you become aware THERE ARE NO TRUST ME DIVES IN THIS REALM!
You must be able to handle yourself.

Leave the REC world without the proper gear,training, mindset your risk increases significantly for a dive related accident.
Not trying to scare you or sway your plan but make you aware.
AWARENESS IS GOLDEN!

CamG

I have absolutely zero desire to do deco dives on a regular basis. I asked my question because this is probably one of the only times I would do a deco dive in my life, knowing in advance I would do it. I dive with lots of tech divers, those with little plastic cards certifying them as having taken the AD/DP class, as well as a few I have real respect for. Frankly, taking the class and then never / rarely using the training scares me more than not getting the training in the first place, because skills decay when not used, and it seems like technical diving skills decay more rapidly than recreational skills. I've never understood the logic of tech diving certifications not expiring if not regularly dived and practiced. The majority of my dives (a few times a week) are So Cal shore dives, frequently through surf, so the thought of a multiple tanks is not only unappealing (e.g., walking across stretches of sandy beaches with doubles), but also greater risk due to entry / exit with waves. Shore dive depths here rarely exceed 60 ft, so little chance to practice deco procedures. When I do boat dives, I want to see interesting stuff, and figure I'll never even get to do enough recreational dives to see everything I'd like to

---------- Post added January 29th, 2014 at 12:15 AM ----------

I have been to Tufi and the diving there is generally very easy. The wrecks of Blackjack B-17 and S'Jacob are not dives that are usually done by the average diver. In fact, when I went there they did not even do them as they are quite a distance from the resort. If you are experienced, they are rated in the top few wreck dives anywhere in the world.

Most of the dives will be walls, so you can go to whatever depth you need to want to go to. If some of the group opt to do the wrecks, then I am sure that alternatives will be offered on the way back from them.

As to the wharf dive, it is excellent, with a PT boat remains the main feature. Again, you can go to whatever depth you want, it is in a fjord.

My friend who invited us spent a while at Tufi when she was cruising the south Pacific on her boat, and raved about the diving, including the deep wrecks. Other friends who sailed around the world spent a bit of time in Vanuatu and did many dives on the Coolidge, which they thoroughly enjoyed, and it sounds like the deco diving there works similarly to Tufi. This is a trip put together for experienced recreational divers, so I expect many going will be interested in the wrecks for one day. I love wall dives, but wrecks are sometimes a nice change of pace, and it will be easier to drag my wife to deeper wrecks in warm water than the cold water wrecks we have here

 

[Foxfish]

I have absolutely zero desire to do deco dives on a regular basis. I asked my question because this is probably one of the only times I would do a deco dive in my life, knowing in advance I would do it. I dive with lots of tech divers, those with little plastic cards certifying them as having taken the AD/DP class, as well as a few I have real respect for. Frankly, taking the class and then never / rarely using the training scares me more than not getting the training in the first place, because skills decay when not used, and it seems like technical diving skills decay more rapidly than recreational skills. I've never understood the logic of tech diving certifications not expiring if not regularly dived and practiced. The majority of my dives (a few times a week) are So Cal shore dives, frequently through surf, so the thought of a multiple tanks is not only unappealing (e.g., walking across stretches of sandy beaches with doubles), but also greater risk due to entry / exit with waves. Shore dive depths here rarely exceed 60 ft, so little chance to practice deco procedures. When I do boat dives, I want to see interesting stuff, and figure I'll never even get to do enough recreational dives to see everything I'd like to

So you don't like the idea of doing the required training for deco diving. The shallow dives sound good to me.

 

[drrich2]

Trust me dives are a contentious issue on the forum, often derided. On the one hand, most of us rely on trusting others at some points in our lives; plane pilots, Physicians, etc... Many people at least rely on dive guides for navigation on tourist dives such as in the Caribbean and the Florida Keys.

On the other hand, threads discussing Blue Hole diving out of Belize give rise to op.s allegedly taking 'green' divers on inappropriately risky aggressive dive profiles to excessive depths on single AL80 tanks.

The dive industry is not as tightly regulated as the airline industry or medical field, from what I understand. Thus, you don't run an independent analysis on medication from your pharmacy, but if you dive nitrox, you're supposed to analyze each tank. It's less like taking a flight on American Airlines and more like hopping in your buddy's little private plane that he built himself.

Since deco. diving at non-rec. depths beyond your current training is deemed quite risky, many people will advise against it. Evidently this op. has done this dive profile with other people (wonder what numbers, and how they arrived at this profile). Then again, a lot of people have bounce dove the Blue Hole without evident harm.

Wonder what happens if a diver has a problem causing an extension of bottom time; somebody gets a free flow late in the dive, or narc.'d into confusion and takes time to deal with, etc... Can they modify the deco. profile on the fly to account for that?

It's up to you whether to take the risk. Are you planning to take your wife on this dive, too?

Richard.

 

[Foxfish]

I recently did some overseas diving to about 35 m with a guide. I had my own dive computer and followed it. When I approached NDL's I signaled to the guide and ascended even though to a large extent he was leading the dive. If you've done the required training and the guide is flexible, what is to stop you from following a pre-agreed profile.

If you can get the guide to work with you then the other major obstacle is doing the training.

 

[Subcooled]

Do the dives, if you wish, but get some training beforehand. Also do some planning in advance so that you know what to expect. If you don't get some sort of training/guidance, do some planning, and get plenty of gas, then the dive will not be a relaxing one.

45m on air is pretty demanding. Gas narcosis affects you in a very concrete way. Adding the effects of increased gas consumption rate at depth, limited air supply, quickly accumulating deco time, and the reserves needed for you and your buddy, to narcosis, the result is not a very relaxing dive. Would a free flow situation or some other problem affect your regulator, then you would not enjoy the situation at all. The dive can be made more pleasing by simply carrying plenty of gas and having planned it well and in advance.

When minutes count... and the mind is fading... a lot of planning must be done prior to the dive.

The above comments are not based on litterature, regulations, or things learned from an online forum. I actually dived to 45m on air quite a few times, and from personal experience I must say that a) things happen and b) you should spend a few nights doing contingency plans and gas calculations. It is really embarrassing to run out of gas while doing deco :|

Some sort of instruction would be a very healthy thing and would make the dive more fun.

 

[AfterDark]

After Dark, you simply can't go around telling lobotomised mushrooms that the earth isn't flat without retribution.

To the OP, we have a saying......."you'll never never know if you never never go".......if you do go, don't tell the mushrooms on here about it as they clearly have no idea about the advantage of diving in warm tropical water. :ssst:

If you don't go, ..........can I take your place?

Look here’s the OP:
“Without adding to the lively discussion in a couple of other recent threads about recreational divers going into deco, I am now potentially faced with a good dilema on the subject. I'm a relatively competent and experienced recreational diver with absolutely no plans of getting into technical diving. A friend invited us along with a number of her other buddies to go to Tufi Resort in PNG; if we take care of the airfare, this friend will pick up accommodations for everyone who joins her (and before anyone asks, I'm positive the offer does not extent to online friends of friends from Scubaboard!)

I started looking at the Tufi web site to find out about diving there, and there are some interesting wrecks; see Wreckdiving for the descriptions. These dives are clearly geared toward recreational divers, but are described as having only 10 minutes of bottom time and "a decompression dive with max depth 45m. Deco stops are compulsory and surface interval of 4 hours is mandatory before the second dive." There's even a muck dive off the wharf that includes a Land Rover on the bottom also described as a deco dive

What would you do in my situation and why? Just do the shallow muck diving and local reefs? Blindly follow their prescribed profile? Take a deco procedures class before going? These are 100 minute dives with stringent preplanned safety stops along the way, so I presume the resort has done this before, with plenty of tanks staged for those who can't make an Al80 last the whole dive, therefore assume there is some additional air besides the single on my back. Unfortunately they don't appear to have nitrox there. It sounds like there is a chamber in PNG”

Nowhere in there is he asking advise as to what he should do, he wants to know what someone else would do. So I told him. I didn’t say he should, nor did I say he should get training; why? Because he didn’t ask for advise; he was taking a poll.

A rudimentary understanding of deco theory and a set of navy air dive tables is all that is needed to plan and execute the dives the OP is describing. Or as Akimbo posted "It isn't rocket science, study up a little, and have fun".

 

[RickyF]

V-planner shows that for a 135' dive on air with a 10 minute bottom time (includes descent, so actually about 7.5 min on bottom) you need to stop at 30' for 2:15 and 20' for 10 minutes of deco. This is a deco dive and unless you have trained and have planned accordingly, you are asking for trouble. Get the advanced deco training and then go enjoy yourself safely.

 

[iluvtheocean]

i would stick with the muck & reefs -- would not do a 130+ ft deco dive on air & AL80s, especially on somebody else's gear & dive planning.

 

[Lorenzoid]

Looks like clownfishsydney's is the most practical answer, based on firsthand knowledge: So long as you stick with the wall dives and don't venture out to the wrecks, you'll have a great time.

I have been to Tufi and the diving there is generally very easy. The wrecks of Blackjack B-17 and S'Jacob are not dives that are usually done by the average diver. In fact, when I went there they did not even do them as they are quite a distance from the resort. If you are experienced, they are rated in the top few wreck dives anywhere in the world.

Most of the dives will be walls, so you can go to whatever depth you need to want to go to. If some of the group opt to do the wrecks, then I am sure that alternatives will be offered on the way back from them.

As to the wharf dive, it is excellent, with a PT boat remains the main feature. Again, you can go to whatever depth you want, it is in a fjord.

If you find yourself tempted to do the wreck dives, then it sure WOULD add to the "lively discussion" in other recent threads. That kind of temptation for a recreational diver to push the limits of his training and experience is exactly what those other threads are about.

Without adding to the lively discussion in a couple of other recent threads about recreational divers going into deco, I am now potentially faced with a good dilema on the subject. . . .

This trip may seem like a once in a lifetime opportunity that warrants pushing the envelope, but if it is something that really attracts you I'm sure you can find a way to go back there and dive it "by the book."

 

[tomfcrist]

Geoff,

Yes tourist destinations have doubles...bioniare, key largo, etc all have ops whom teach tech. If back mounted doubles aren't available, go side mount.

The advise you have been given is sound....but if you choose to go and dive deco blindly, that is your prerogative. If you are as niece about the possible issues with the type of dive you have described as I think you are, I will be anxiously awaiting dandy dons post in A&I sometime during your trip.