Tech specs on the trimix Holsten wreck dive.

[Chad Carney]

As a comparison to the recent deep air dive on the Ande, here's the download from my Uwatec computer on the Holsten dive I made July 6th. http://www.spearboard.com/showthread.php?t=31571

The computer does not know it's a 22/18 trimix dive. A smooth ascent is key when using helium.

The dive plan:
BT 12 min.
Stops: 80' - 1 min, 70' - 1, 60' -1, 50' - 1, 40' - 2.
Switch to 65% O2: 30' - 2, 20' - 3, 10' - 5.

For some reason, when using stage tanks, my Air Z O2 computer sometimes will not display air consumption information. None available here. I had 1500psi remaining in my HP120 after the dive. Max deco on my Uwatec was 11 minutes.

Mike Rieth and I gear up. Didn't know it would be 66*F down there. I should have worn my 3mm full at least, but I just tore it badly. Funny how you're not cold when there are fish to shoot!

Dive #2953. The wreck of the freighter Holsten.

Chad

[dagodiver]

Very cool Chad.!
I have only dove the Holstein once but my planned bottom time was 40 minutes so I got a real good look at it.


Dago.

[Blood Vessel]

Thanks for the info.
What was your tank set up? Sounds like single steel 120 likely with H valve and dual regs and then a single pony with EAN 65.

[Chad Carney]

That's it dead on Jason... but I will have my 6 cu ft air bail-out bottle from now on as well.

Also the closer to 80% O2 the better for the deco bottle. Often for small time mixers like me, the mid 60's is all we can muster.

Chad

[jadairiii]

I am not posting this to debate different procedures or personal preference vs. DIR. But since Chad is an instructor, I am giving those that may be looking into tech diving/tech spear fishing at least an alternate view of this dive profile and how it may be done “differently”.

First off, the bottom mix seems a bit odd, PPO2’s are too high for the “working” part of the dive and the Helium is ridiculously low. Remember that high PPO2’s will cause greater retention of CO2 which intern will mimic or increase narcosis. This is especially important to consider since clearly this is a working dive and spearing fish will increase your workload and task loading. Which brings up the low helium content. Helium is good, more helium is better, especially if you are working hard and diving deep, it reduces narcosis, is easier to breath, “increases” performance of your breathing gear and makes deco easier as long as you remember to start your stops deep enough. I for one would not consider diving that depth unless I was using 18/45 mix. Low PPO2 (1.2) and gives you and EAD of about 75’(compared to the 1.52 with the 22/18 mix, EAD of 150’). And as for deco obligation, for a bounce dive like this one it would only increases your deco by no more than maybe 5 to 10 min, if that.

As for deco gas, the 65% is just about worthless (and don't get me started on 80%!). There are better options, one is to mix EAN 50 (MOD 70) and breath it from 70’ up, with a minimum of 3 min (I like :5) at 70’ since it takes a minimum of 3 min. for the gas to enter your body and do any “good”, you are now at the resting part of you dive so 1.6 PPO2 is OK and spending a little extra time at that level will give a better start to the “washing” of the bottom mix. But a point to consider is that this deco gas is used in conjunction with the 18/45, you can’t mix and match this to be of any benefit. Second option is to go with straight O2 at the 20’ stop, only down side to the O2 is that this dive profile is so short that your benefit would be very limited. Even though I would never suggest this, I do know divers that would not even consider this dive profile as requiring deco at all, even diving 18/45 since your bottom time was under 10 min, just surface at 30’/min. But as stated I would not, I would still do some minimum deco.

Now, there will be those who claim that the cost of an 18/45 mix is prohibitive, I disagree, look at what it cost you to get to the dive site (gear/guns/school/boat/gas/food), why get cheap with the one “tool” that makes your dive the safest and most enjoyable? And, as to those who claim they are good on air deep, bull shit, you should see yourselves down there fumbling around (Duke did a study that found noticeable impairment at 50’).

I did my share of deep air BS dives in the mid 90’s (considered myself good on air, ahhhh!) and would never consider going back to that again, I like a clear head and there is no debate on the increased safety level. This was a very basic overview and I could go on for pages on the additional benefits of diving higher helium and alternate deco mixes, but you all can do that on your own, the information and history is out there, easily accessible on the internet and books.

John

[dagodiver]

When I was diving the Holstein on the charter that I took myself and my buddy dove it in the tech/wreck style but everyone else dove it in the tech/spear
style and we all got along just fine. I am a very open minded tech diver and learn alot of great stuff from all types of divers. John you are putting way to much faith in your "group" of divers. An 18/45 for a bounce dive to the Holstein is not by any means the perfect gas there is no "perfect" gas it is just that some people think there is. Actually there is the perfect mix...lets see it is called a ECCR.! :cool:
As far as being narced call it what you want but these guys put some fish in the boat and that is why the went.
The "dont get me started" thing.......lets see I learned that any gas with a higher O2 on the way up is a deco gas, 80% works fine. I know "you" guys have a million reasons why it is the "str..e" thing to do but it gets you out of the water and that is what it is for. I only dive 35/25, 50/15 and 100% myself but that does not mean that something else wont work.
YMMV


Dago.

[jadairiii]

When I was diving the Holstein on the charter that I took myself and my buddy dove it in the tech/wreck style but everyone else dove it in the tech/spear
style and we all got along just fine. I am a very open minded tech diver and learn alot of great stuff from all types of divers. John you are putting way to much faith in your "group" of divers. An 18/45 for a bounce dive to the Holstein is not by any means the perfect gas there is no "perfect" gas it is just that some people think there is. Actually there is the perfect mix...lets see it is called a ECCR.! :cool:
As far as being narced call it what you want but these guys put some fish in the boat and that is why the went.
The "dont get me started" thing.......lets see I learned that any gas with a higher O2 on the way up is a deco gas, 80% works fine. I know "you" guys have a million reasons why it is the "str..e" thing to do but it gets you out of the water and that is what it is for. I only dive 35/25, 50/15 and 100% myself but that does not mean that something else wont work.
YMMV


Dago.

Since I referred to 80/20 deco gas and Dago reference that, let me put 80/20 into historical perspective for those of you new to tech diving.

In the early to mid 90’s virtually no one was diving helium mixes at all, those that were were taking it really deep, below 200'. For 200 and above air was the gas of choice, and the deco gas was O2 (in the old E bottles). Further, there were very few commercial deco programs available, most divers were diving computers that were based on the navy tables, so all of your deco was in the 30’ and above range, deep stops were unheard of (pre-Pyle). In comes IANTD (IAND) and sees a problem, they become worried about the masses of new tech divers bobbing up and down at 20’ breathing O2. They do not like the idea of someone drifting down to 30’ and toxing. So they come up with the idea of 80/20, a “safer” alternative to O2. Never was it considered a better or optimum gas for off gassing. Remember that these were the same people to brought you the color coded “poodle jackets” to keep you from hitting your back mounted O2 gas (or 80/20) when switching regulators on your independent doubles when whacked on air at 200’.

80/20 was solving a problem of poor buoyancy control and covering a liability issue for IANTD, is was never considered an optimum deco gas. Many of you would not believe the shit that was being taught then, I cringe when I look at my IANTD Technical Deep Air card I got back in 94’-95’ and think of the crazy stuff we did for that class! :eek: But some how some of these old “wives tales” kind of stuff has become so ingrained in tech diving that a lot of people forget why it first came about. Sure 80% “works” but EAN 50 or O2 works better used at their proper depths, there is no cost difference, so the big question is “why us 80%” (or any other convoluted gas for that matter).


John

[GRIM REEFER]

He's my hero!!! :rolleyes:

[GRIM REEFER]

Sorry about that gruesome sight :D I was joking very much.
But about the deco gasses. I like 50% and 100% too.
That's what I use on all my tech dives and so when I spear I use it then also.
I have all my deco bottles marked with the MOD so I'm not gonna go putting other gasses in them. But I think maybe some people like 80% because they
cant get high pressure O2.
I admit, I'm pretty new to tech diving, But that's almost all I do now. That's all I can think about. I have always loved spearfishing as well and I'm
pretty excited about putting the two together. I also enjoy looking at different gear config. for spearfishing.
I can understand the more HE thing. I don't like being drunk off my ass
at 300' But END of 70'? I guess when you do a top up you would still have a decent mix. But I guess for these guys. If they are comfortable with it,
Why the hell not. I have a few friends that look at me like I'm F#CKED in the head when I tell them about some of the dives I've been doing.
They think I have a death wish. I love life, That's why I dive. And I don't take chances. And I'm sure these guys don't feel like they are taking chances either.
Shane

[Chad Carney]

Sorry it took so long to get back to this thread, but I've been busy shooting fish and lobstering.

First of all, both of my computers read out depth in fresh water, so my max depth was only 197 fsw, END of 142' and a PO2 of 1.55. More importantly I was there for less than 2 minutes, recording a CNS level of only 5%. (The correct temperature was 72*F, read on my back up computer.)

The average depth on the wreck was more like 175 fsw, END of 125', PO2 of 1.4, and in only 4 minutes duration, I shot 2 nice gags with just about zero work, still just 5% CNS. Spearfishing for bottom fish is not hard work when done right. Many of my dives show the "working part" is usually descending and sometimes ascending. This dive was a walk in the park, using only 1100 psi until switching at 30'.

The last 3 minutes of the BT was at 155 fsw, 110' END and 1.26 PO2. Finally incurred 10% CNS, the max for the whole dive.

Reasons for the O2 choice: Entry level TDI students are not allowed to use less than 21%. Spearfishermen are not bottom huggers and the average PO2 of 1.4 is usually the case when mixed for a max of 1.6. I have thousands of down-loaded spearfishing dives to back this up. The longest I've recorded was half the bottom time on a dive not much different than this one, at a PO2 of 1.5. BTW, I'm fine with 1.5, since it gives a diver almost a 3 times benefit on his O2 clock over 1.6, (45 min to 120 min single dive exposure limit.) Going to 1.4 only gains another 25%, (120 min. to 150 min.)

Reasons for the He choice: We planned to do 2 more bounce dives around 140' to 120'. I don't have a lot of faith in the planning programs. Since I have seen virtually nothing in texts, nor heard much about tech divers making lots of repetitive bounce dives, I like to keep the He lower, where it still takes the edge off the narcosis, but keeps the ascents more forgiving.

Reasons for the deco O2 choice: All O2 percentages are of benefit! Ask one of my students on this dive, he's board certified in hyperbarics. 65% is a fine deco compromise for short dives, and allows a MOD of 48' if necessary on ascent. As for planning to use the deco bottle below 30', (80' to 40'), it eats up a lot of volume, that makes it tough to use a single 30 cu ft deco bottle for 3 dives.

BTW, look at the ascent... no bobbing here! My students were right there, level with me for the entire deco from 80'. It was calm, virtually no current, with the boat idling right over top of our bubbles. Not bad for freefloating deco stops! (Saw no reason to blow our floats.)

To summarize my points, this was only a tech spearfishing dive day, part of an entry level trimix class. Sure doubles, a big travel tank and big deco tank could give the dive healthy "best mix" values, but they can also overload a spearfisherman to give him a worse stringer value!

Chad

[fishhunta]

I guess that I "do it wrong" too, along with 98% of this board.
I dive the holstien on air, it worked fine for me. Any helium or deco gasses I view as a bonus.

[dagodiver]

When I was diving the Holstein on the charter that I took myself and my buddy dove it in the tech/wreck style but everyone else dove it in the tech/spear
style and we all got along just fine. I am a very open minded tech diver and learn alot of great stuff from all types of divers. John you are putting way to much faith in your "group" of divers. An 18/45 for a bounce dive to the Holstein is not by any means the perfect gas there is no "perfect" gas it is just that some people think there is. Actually there is the perfect mix...lets see it is called a ECCR.! :cool:
As far as being narced call it what you want but these guys put some fish in the boat and that is why they went.
The "dont get me started" thing.......lets see I learned that any gas with a higher O2 on the way up is a deco gas, 80% works fine. I know "you" guys have a million reasons why it is the "str..e" thing to do but it gets you out of the water and that is what it is for. I only dive 35/25, 50/15 and 100% myself but that does not mean that something else wont work.
YMMV


Dago.


Paul,
Just making sure you didnt miss what i said.

Dagp

[fishhunta]

I definately wasn't directing my comments at you Dago.

[diligaf]

Since I referred to 80/20 deco gas and Dago reference that, let me put 80/20 into historical perspective for those of you new to tech diving.

In the early to mid 90’s virtually no one was diving helium mixes at all, those that were were taking it really deep, below 200'. For 200 and above air was the gas of choice, and the deco gas was O2 (in the old E bottles). Further, there were very few commercial deco programs available, most divers were diving computers that were based on the navy tables, so all of your deco was in the 30’ and above range, deep stops were unheard of (pre-Pyle). In comes IANTD (IAND) and sees a problem, they become worried about the masses of new tech divers bobbing up and down at 20’ breathing O2. They do not like the idea of someone drifting down to 30’ and toxing. So they come up with the idea of 80/20, a “safer” alternative to O2. Never was it considered a better or optimum gas for off gassing. Remember that these were the same people to brought you the color coded “poodle jackets” to keep you from hitting your back mounted O2 gas (or 80/20) when switching regulators on your independent doubles when whacked on air at 200’.

80/20 was solving a problem of poor buoyancy control and covering a liability issue for IANTD, is was never considered an optimum deco gas. Many of you would not believe the shit that was being taught then, I cringe when I look at my IANTD Technical Deep Air card I got back in 94’-95’ and think of the crazy stuff we did for that class! :eek: But some how some of these old “wives tales” kind of stuff has become so ingrained in tech diving that a lot of people forget why it first came about. Sure 80% “works” but EAN 50 or O2 works better used at their proper depths, there is no cost difference, so the big question is “why us 80%” (or any other convoluted gas for that matter).


John

Jada… you’re IANTD history lesson might be called “selective” or “misinformed” at best. I’ll just say Tom Mount knows more about diving than you, me, and the rest of the board combined!

Tech spearfishing has different priorities/concerns than traditional tech or cave diving. Bottom and deco times as a general rule are much shorter. Streamline and simple gear configurations are of more concern due greater risk of entanglement w/large fish. You can never place stage bottles or regulators in a position that they can be ripped away by large fish (or you can never let the fish get between you and your gear). For this reason, IMO, if possible, you need to have a bottom mix that you can deco out on.

IMO, for this wreck I would use a 21 or 22 O2 percent, as Chad choose. I do agree that more helium is better and as a personal choice I would use a 21/35. I would also choose a 50% deco mix (if using 21/35), but any % between 50-80 would suffice with minimal difference in deco obligation. Without running tables, if using a 22/18 mix, 65% sounds about like the optimal deco mix.

BTW, I hear George gave up diving. Is he Ok?

[jadairiii]

Jada… you’re IANTD history lesson might be called “selective” or “misinformed” at best. I’ll just say Tom Mount knows more about diving than you, me, and the rest of the board combined!

Tech spearfishing has different priorities/concerns than traditional tech or cave diving. Bottom and deco times as a general rule are much shorter. Streamline and simple gear configurations are of more concern due greater risk of entanglement w/large fish. You can never place stage bottles or regulators in a position that they can be ripped away by large fish (or you can never let the fish get between you and your gear). For this reason, IMO, if possible, you need to have a bottom mix that you can deco out on.

IMO, for this wreck I would use a 21 or 22 O2 percent, as Chad choose. I do agree that more helium is better and as a personal choice I would use a 21/35. I would also choose a 50% deco mix (if using 21/35), but any % between 50-80 would suffice with minimal difference in deco obligation. Without running tables, if using a 22/18 mix, 65% sounds about like the optimal deco mix.

BTW, I hear George gave up diving. Is he Ok?

My tech nitrox and tech deep air instructor was one of the founding Board of Directors of IANTD, so my history is pretty good, and I was there when it was being taught in 1994-1995.

As for George, I have no idea, never knew him personally, I have no association with WKPP or GUE (not that there is anything wrong with it, great group and based on there exploriation success, some of the best cave divers in the world) and I am not a cave diver. But since you seem very interested in his personal life (which seems a little odd), check out TheDecostop.com, someone posted the same question about him not to long ago.

John

[diligaf]

My tech nitrox and tech deep air instructor was one of the founding Board of Directors of IANTD, so my history is pretty good, and I was there when it was being taught in 1994-1995.

As for George, I have no idea, never knew him personally, I have no association with WKPP or GUE (not that there is anything wrong with it, great group and based on there exploriation success, some of the best cave divers in the world) and I am not a cave diver. But since you seem very interested in his personal life (which seems a little odd), check out TheDecostop.com, someone posted the same question about him not to long ago.

John

Who was your instructor? Jim Mims?

As for George, my mistake, you just came off with a little holier-than-thou attitude (or at least that is my perception). Somehow that made me think of George... a little odd indeed :rolleyes:

In my book though, George is alright. He may talk a lot of sh*t, but he is one of the few that can back-it-up.

Dave

[dagodiver]

In my book though, George is alright. He may talk a lot of sh*t, but he is one of the few that can back-it-up.

Dave

For sure, whatever you think of him you cant take away his diving skills.
He has been there and done that and has the storys to share. He also makes the best yacht towers PERIOD. I have run lots of big boats and you can tell his tower's from a long ways away.!

Some of my best dive trips on the East coast have been with Jim Mims!

Dago.

[jadairiii]

Who was your instructor? Jim Mims?

Yes, he is a great guy and anyone that started diving in the early 90's has at least one (if not many) Jim stories. Just diving off the Reef Cat then was an adventure! Did my first tech dive off his boat in 1994, and he was the only game in town for many years. Great capt and great boat for tech.

John

FYI, Dago you are right about PipeWelders, in 1986 they did some work on a Rybo tower we had and it was fantastic!

[aue-mike]

Yes, he is a great guy and anyone that started diving in the early 90's has at least one (if not many) Jim stories. Just diving off the Reef Cat then was an adventure!

The Havanalyser...