Cave/Wreck and OC trimix/rebreather trimix

[ComputerJoe]

If everyone hasn't caught on by now, they will realize sooner or later that there are some certifications that don't teach you much if anything. I'm wondering if we are ever going to see some certifications merge into one. Two that come to mind first are the cave(cavern)/wreck certs.

The differences between those two certs are so minimal it would make sense to come up with a wreck/cave certification and avoid the repetition. I for one would be more likely to set aside the time for a "doubled" cert than just a single and waste time rehashing stuff you have already learned. I just don't buy that if full cave certified that you would not be certified for wreck penetration. And the reverse is true as well. Although there maybe some subtle differences, what do you think? Could the differences be handled in less than an hour?

Right now I'm looking at trimix certification, if you are certified to dive trimix why then is another class needed for rebreather trimix? I know that the agencys are trying to give instructors more classes to teach but the time we students have available for these is dwindling. It seems if you are working now that 40 hour per week job's are going away.

 

[TSandM]

I haven't taken a formal wreck pen course, but there are a LOT of things that are different between wreck and cave diving. Just because you're going into an overhead and running line, doesn't make the diving the same. Wreck penetration involves studying the wreck (plans, etc.) and dealing with the hazards of the interior spaces (wires, cables, metal protrusions that can chafe or cut line). In addition, there are protocols and procedures for wreck diving that aren't involved in caves (setting shot lines, for example). Caves, on the other hand, can involve more complex navigation among a profusion of permanent lines. There are certainly skills that transfer, like reel handling, light signals, and non-silting propulsion, but they are different environments. Someone who has learned one can probably move more rapidly through a class to do the other, but I don't think they should be combined (and it would be logistically difficult as well, because diveable caves aren't very often where penetrable wrecks live!)

As far as rebreather trimix goes, are you suggesting that someone learn to dive a rebreather AND dive trimix in the same class?

 

[wedivebc]

I am amazed at the number of people who are trying to fast-track their card collection. If you find any level of training a waste of time, why bother? Overhead and CCR diving are some of the riskier aspects of this sport and trying to shortcircuit the training is going to get someone killed.
As Lynne said there are quite a number of differences between diving in a cave and diving in a wreck and there are a few similarities but there is no way any agency (or decent instructor) could teach a dual purpose course.
As far as RB trimix and OC trimix is concerned the differences are plenty.

 

[Tienuts]

Right now I'm looking at trimix certification, if you are certified to dive trimix why then is another class needed for rebreather trimix?

While the gas physics are the same, the skill set for CCR Trimix is entirely different than OC trimix. So is the gas planning.

 

[battles2a5]

I would hardly equate the classes you listed to the a useless PADI cert.

If you don't think you need the cert, don't take the class. As others have noted, there are definitely differences. Not all wreck divers will be cave divers and vice versa. I agree that there is limited value added for a cave diver that is experienced in wreck diving, but that is a personal choice.

OC Trimix vs. CCR Trimix is a different animal. I'm not doing CC yet, but there is clearly a very new skill set that needs to be mastered before you jump into mix on the the unit. Just like you need to master the basics on OC before you dive mix you need to master the CCR before you make the jump. If you have a OC trimix cert nobody is going to stop you from getting fills, but if the entire technical diving industry feels these classes are a good toll gate for this kind of diving, I would tend to agree with them.

 

[DA Aquamaster]

There is some overlap, but I'd argue the need is in the other direction - more specialization.

Consider for example the humble TDI Advanced Nitrox/deco procedures combination. You get what amounts to one course and one set of standards regardless of whether you ultimately dive wrecks or caves and the course is very much off shore oriented.

It requires you to shoot lift bag, etc as would be the case for diving offshore wrecks, however it does not even begin to tell you what to do if you require a a 20' stop in a cave where you ascend well below 20' on the way out after the deco stop.

In effect, once you get the cert you need to add to that to adapt the basic skills to another environment.

However I do agree that taken in total there is some room for flexibility. For example I took cavern to learn and improve line handling skills in anticpation of advanced wreck with the same instructor but went on to do intro to cave and did not bother with advanced wreck at the time. Later the instructor offerred to just throw in the advanced wreck cert as part of the trimix cert. Given the wreck dives being done in the trimix course and the cave training already received, the additional skills over and above both intro to cave and trimix were fairly minimal and mostly academic in nature (different threats, etc) and the in water stuff could be practiced on the trimix dives.

As another example, Marci will soon be taking advanced nitrox and deco procedures immediately prior to full cave so she will also be able to double up a couple of the dives at the end of the Adv. Nitrox/deco course with a couple of the dives required for full cave - and will benefit from getting course exposure to deco procedures in the cave environment. Best of both worlds.

In contrast, I did advanced nitrox and deco procedures years ago and then on my second deco cave dive found myself learning on the fly the best way to handle deco exiting a high flow system. Less than optimum. It also became obvious that the practicalities of the environment can drive things like choices in mix, etc. For example, if doing a one deco gas dive, 50% makes a great deal of sense off shore, but 100% O2 is usually a far better choice in a cave environment.

 

[grazie42]

Having taken both tech wreck and (full) cave, I disagree pretty strongly that they are "the same course"...They are both overheads but like others have already pointed out, the hazards and planning of those two kinds of dives are completely different.

I have OC tmx which does allow me to use He from day 1 on my RB. But when I start doing "proper" mix dives, I´ll take another RB-course because both the skill-set and the planning is different.

This is not to say that there aren´t commonalities between the courses, the physics of mix diving are the same whether OC or CCR for example, but having taken both (in the wreck/cave area) I feel pretty strongly that there is benefit to both. In fact, any time you spend something on the order of 5 days with an instructor and don´t learn or improve enough to consider it time wisely spent you should ask for your money back and use a different instructor...

ymmv obviously...

 

[ComputerJoe]

Ok, so there are some differences, it still looks like there are more similarities. Paying $1500 for each cert and covering so much common material is inefficient and a deterient to diving within your training, this encourages divers to "just go out and do it." Maybe what's called for is a class that covers the common skill sets in both specializations. Or maybe a set of abbreviated classes if you already hold one cert.

$1500 for a rebreather diver to get trimix certified when he is already OC trimix certified. Or paying for a full wreck diving class for a full cave certified diver seems obtuse. This IS NOT short cutting ones training, it is a more logical use of ones time and money.

I expected negative comments from those who might be benefiting from things the way they are. I have the right and duty to question it, advancements in our sport only happen when someone questions why things are the way they are.

I hope to see a beneficial commentary develop around this question.

 

[grazie42]

I disagree that the material is that common...

IANTD has a combination course for the cavern/adv. wreck level and I think it makes some sense there (Ive taken that course) but for the more advanced levels I believe that the enviroments, and the complexity of the dives in those enviroments do justify separating the two...

I guess my question is if you have taken "both"? So that we can see "where youre coming from"...

 

[ianr33]

I can see both sides to this.
I'm Full Cave and Normoxic Trimix certified.
Do I really need to do a wreck course if I want to do a reasonably straightforward wreck penetration with an experienced buddy?
Similarly I would have no problem doing a 240 foot dive in a familiar location,although officially I need Advanced Trimix for that.

Training agencies are in the business of selling courses. As far as they are concerned,the more courses the better.

At some point a diver should be able to decide for himself when he needs formal instruction and when diving with experienced buddies is enough.

How many divers doing 350 foot dives have a certification for that?