Cave Diver Harry

First Dive on the Nomad JT

2011-07-23T19:25:00.003-04:00

Stuart Brand, publisher of The Last Whole Earth Catalog, once remarked that “Tools are the only material possessions worth having.” When you dive for a living, your various pieces of dive equipment are your tools.

The notion of acquiring yet another Thing seldom excites me. I have to admit, however, that I was really, really looking forward to getting my hands on Dive Rite’s new Nomad JT. (The JT stands for renowned sidemounter James Tolin, whose design ideas and input shaped this Nomad’s development.)

Have you ever made a much-anticipated purchase, only to be disappointed when the product did not live up to your expectations? I had high hopes for this Nomad but, as things turned out, it was not what I expected. It was better. Way better.

The first thing you notice about the Nomad JT is how much cleaner and more streamlined it is than its predecessors. Standard Nomads are based on the Dive Rite Transpac harness and can theoretically be modified to dive back-mounted singles, doubles and rebreathers. In contrast, the Nomad JT is a solid, one-piece unit designed for a single task: open-circuit sidemount.

The back of the Nomad JT is made from a single piece of Dive Rite’s extremely durable and tear-resistant Superfabric. Given how much serious sidemounters are prone to rubbing their rigs against ceilings and treacherous rock “dragon’s teeth,” this is a good idea.

In fact, the only thing you will find on the back are the start of the crotch strap, a plate with side-oriented D-rings for clipping reels and other items to, and the normal mounting rails for tanks. There is also a small strip of daisy loops located in the small of the back, should you want to mount a light canister there.

Even the bungee cords are mounted on the inside, so as not to create a risk of snagging or entanglement. Overall, it is extremely clean.

On the front of the Nomad JT, you will find an equally innovative harness system, made from two-inch webbing. The harness runs freely through oval rings at the top and sides of the air cell. When you don the harness and fasten the waist strap, you not only tighten the shoulder straps, you snug the air cell around your shoulders and waist.

There are three pull dumps on the Nomad JT, all mounted on the front side. Two are located at the bottom (making it possible to back dump with either hand); the other is dead center at the top. The inflation hose is inverted (as most sidemounters seem to prefer); you vent the air cell during ascents by pulling down on a cord attached to the protected top dump and routed through a tube on the left shoulder strap.

In the center, roughly between the place where your shoulder blades would be, are a series of daisy loops for attaching the bungee cords. This makes adjusting bungee cord length easy.

The bungee cords exit the back through either of two slots located on the outside of the air cell. This protects the bungee cords while still enabling them to hold the air cell snugly against your back. Dive Rite’s ring bungees are standard — although other types of bungee cord systems will work.

Diving the Nomad JT

When I first acquired my Nomad EXP three years ago, it took me a number of dives before I found a way of configuring it to best meet my needs. In contrast, my adaptation to the Nomad JT was almost instantaneous. In fact, the only thing that required getting used to was the fact the inflator mechanism and pull dump were in slightly different positions than I was used to.

Despite its low drag and snug fit, the Nomad JT was extremely comfortable. My bottles tucked in nicely along the sides and, even though I got the sense they were a couple inches further back (which makes wearing them more comfortable), I had no difficulty maintaining good trim — even though I was wearing a wet suit.

Of course, one of the things I was most curious about was whether or not I could squeeze through tighter openings than I was able to in my bulkier Nomad EXP. And the answer is, yes. Abso-freakin-lutely.

After my first dive on the rig, I plan to make a few small adjustments, trim some strap length, etc. What I will not have to do is majorly re-engineer the harness, which is something a lot of sidemounters find themselves having to do with other rigs.

At the moment, however, I’m a real happy camper.

Zero to Hero in Six Days?

2010-10-08T22:27:00.001-04:00

It’s Possible, but Definitely Not for Everybody: For the average person, a week off from work works out to eight days (two weekends and week in between). Now factor in a day at each end for travel and you are left with six days for diving.

Unfortunately, if your goal is to get your full Cave Diver certification within that time frame, you are pretty much screwed. (Or, you used to be.)

The minimum time frame to go from no overhead training to full Cave Diver with organizations like the NSS-CDS has always been seven days — that’s assuming you do the Cavern and Basic Cave phase in just three days.

And that’s probably a good thing. The average person needs at least eight full days to really do this training justice — and benefits greatly from breaking it down into at least two segments, and possibly getting some experiential diving in between.

This traditional approach to Cave Diver training also assumes some factors that are not always present.

It assumes students may have little or no prior Tech Diver training or experience, or time spent diving anything other than recreational dive equipment.

It also assumes that a substantial portion of those eight days will be spent in the classroom, covering material that could easily be mastered ahead of time through self study.

Are these factors always an issue? I used to think so. Last year, however, I had an experience that changed my mind.

I was working with a student from the Reno, Nevada, area. He was an accomplished tech diver, with qualifications through Trimix — and a lot of real-world tech diving experience in some very cold water.

His goal, on his first trip here to Florida, was to try to get through the traditional Cavern and Basic Cave Diver courses. As I knew little about him, I said, “Theoretically, we can do that in four days — but let’s allow six…just in case. We’ll take it one day at a time and see how it goes.”

At that time, I’d just finished the first draft of the self-study materials that all my students now use. This seemed a good opportunity to try them out.

As is usually the case with these materials, as the student worked through them, we spent time on the phone and exchanged a lot of e-mails, clarifying one point or another. By the time he was done, the student had spent the equivalent of a full day in the classroom mastering all of the academics for full Cave Diver certification.

All he had to do upon arriving here in Florida was take the written test, do the land drills and get in the water. By the end of the first day (the only one that went past 6:00 in the evening), we had made four cavern dives and spent over 100 minutes in the water.

Dive times on training dives at the Cavern and Basic level are restricted by gas and decompression. Therefore, where on a normal day at the Apprentice or Cave Diver level, you might do two 50-minute dives, at the Cavern and Basic level you can easily do four 25-minute (or longer) dives and not be in a rush. This was how our second day went.

I’d said going in that “We’d see how things went.” Well, obviously, they were going exceedingly well.

For the next four days, we did two 50-minute (or longer) dives at the full Cave Diver level. By the end of six days:

We had made the 16 required cavern and cave dives.

We had accrued over 600 minutes of bottom time.

We had done all of the required skills…repeatedly.

Technically, we had not met all of the requirements for NSS-CDS Cave Diver certification — only because we had accomplished this in six days, not seven. Ironically, we had met all of the requirements for PADI Tec Cave Diver, which are more stringent, but specify only minimum number of dives and minutes of bottom time.

So my student went away with a (fully earned) PADI Tec Cave Diver card. I suppose he could have qualified for CDS certification, if you wanted to count all the time doing self study, and all of the phone and e-mail conversations as the equivalent of the full day many of my fellow instructors still spend in the classroom.

We’ve all seen those infomercials where, by buying into some get-rich-quick scheme, “real people” claim to be making “thousands of dollars every month, from home.” Then, at the end of the commercial, you see the small-print disclaimer: Results not typical.

That is certainly the case here. My student was able to accomplish what he did here only because of his extensive prior tech diver training and experience. (Which, by itself, does not qualify you to cave dive — but makes a big difference learning how.)

I’ve always said I would never do an eight-day, non-stop Cavern-through-full-Cave-Diver course. It’s too much, for both the student and the instructor. Given the same set of circumstances, however, I will do the six-day “Zero to Hero” course described here.

There are some limitations, though:

First, students have to meet the prerequisites for PADI Tec Cave, which include training through the PADI Tec Deep Diver level, or its equivalent from another agency.

Second, students need to have logged at least 25 dives in full tech-diver gear, including doubles and deco or stage bottles.

Third, students need to make the time to complete at least eight hours of self study before the course begins. (Okay, all of my students do this now anyway.)

Finally, students need to understand there is no guarantee of completing all of the necessary requirements in six days — to the instructor’s satisfaction.

If students need to come back, they need to come back.

As I said going in, this is not a program for the average student. If you live within reasonable driving distance of north-central Florida, it is to your benefit to break training down into at least two four-day segments.

If you are flying in from out of the area, your time is limited, and you have the prerequisite tech diver training and experience, this may be a viable option. It’s at least worth discussing.

Introducing PADI/DSAT Tec Cave Diver

2010-10-08T22:23:00.002-04:00

Okay, let’s be honest here. If you say the words PADI Cave Diver to some folks, they recoil in horror, envisioning barely qualified Open Water Divers who complete an “easy, convenient” online study program, then knock off the required in-water training requirements in a day.

Of course, as with so many of PADI’s critics, these folks haven’t got a clue what they are talking about. The fact is, the requirements to both teach and take the PADI Tec Cave Diver program are, arguably, the most stringent for any program of its kind.

To start, you can’t teach this program unless:

You are already a fully certified Cave Instructor with NACD, NSS-CDS, IANTD, TDI or NAUI.

You are also qualified as a PADI Tec Deep Instructor.

You’ve proved that you can actually do a decent job teaching this program.

To take this course, students need to be certified to the PADI Tec Deep (Tec 50) level, or hold an equivalent certification from another agency. (That’s typically six or more days of training and twelve or more dives right there.) Having this prerequisite helps ensure that students:

Are familiar with the equipment they will use and the procedures for using it.

Have mastered basic decompression procedures.

Have buoyancy control and propulsion skills that will enable them to pose less of a risk to the fragile cave environment.

Will be able to learn more in the same period of time, because they are building on prior knowledge and skills, rather than mastering new ones.

Additionally, the PADI Tec Cave Diver curriculum not only covers all of the knowledge and skills taught in traditional cave diving courses, it places a heavy emphasis on being considerate of other teams, and planning dives in such a manner as to minimize the impact on caves.

To date, only a handful of instructors have qualified to teach this program (and most of them are using our 106-page training outline, knowledge reviews and final exam). If your goal is to acquire this very prestigious Cave Diver rating, we can help.

Note: Even if you don’t meet the prerequisites for PADI Tec Cave, you can still qualify for Cave Diver certification from NSS-CDS or IANTD. We teach the same quality program regardless. That having been said, we do encourage students to have at least some prior Technical Diver training before becoming a Cave Diver. Doing so helps you learn more and is just plain better for the caves.

Okay, So What Exactly Is a “Safe Exit?”

2010-03-17T20:28:00.007-04:00

Both NSS-CDS and IANTD training standards require that cave diving students maintain a continuous guideline to a safe exit. What they do not make as clear is exactly what constitutes that “safe exit.” The problem is that safe exits are like pornography — hard to define, but you know them when you see them.

Safe exits are also conditional.

What constitutes a safe exit for an experienced diver with hundreds of dives in a particular cave system may not be as safe for a new cave diver who is unfamiliar with the site.

What is clearly a safe exit in the middle of the day may not be at night, or when the basin goes tannic.

So why not just maintain a continuous guideline to open water? That’s what we used to require (and some training agencies still do).

The problem with tying off at the bottom of the open water basin is that, depending on circumstances, it may not be sufficiently safe — or it may create more problems than it solves.

Before going any further, I should mention that this article is aimed primarily at those of us diving in north-central Florida. I can think of few sites in Mexico where it isn’t just as convenient to tie off in open water as it is just inside the entrance, or where there is any significant down side in doing so.

If you cave dive in Florida, however, you are most likely all too familiar with the issues I’m going to address here.

What’s Wrong With Tying Off in Open Water?

Possibly nothing…and, possibly, quite a lot.

The basic theory behind tying off at the bottom of the open water basin is that, should you return to your primary tie off and find it enveloped in zero vis, all you need to do is go straight up and you will surface in air. This is a nice theory. In practice, it may not work.

To start, if you try to surface in zero visibility without the benefit of a guideline, you may find yourself trapped — and blind — under an overhang or log.

You may even find yourself accidentally swimming back into the cave (it happens).

Therefore, if you are starting out in bad visibility, or you think there is any possibility the vis could zero out while you are in the cave, you should not be tying off at the bottom of the basin. Where you need to be tying off is at the surface. This is the only way to be guaranteed of getting back there.

Anyone who has dived Little River when the entrance is under a layer of tannic knows about tying off to the stairs.

Every summer, when Peacock I succumbs to an algae bloom, the gold line gets extended from the cave entrance to the first step.

Recently, two divers who entered Madison Blue while the river was rising returned to find a basin filled with tannic water and had to hunt for their deco bottles. They would have done well to run a line from the stairs and clip their deco bottles to it.

What about the more common situation — a crystal-clear cave entrance with no possibility of the vis zeroing out during a dive? How often have you seen the following at some of our most popular north-Florida cave sites?

You are exiting Devil’s Ear and want to get out as quickly as possible to keep deco to a minimum. Unfortunately, you find your exit blocked for several minutes by a team of divers struggling to run a primary reel through the narrow opening from open water.

Same situation, but this time you are fortunate enough to not find a bottleneck of divers struggling with a reel. What you do have to contend with, however, is a spider web of poorly run guidelines, waiting to entangle the first hapless diver who gets too close to them.

At Peacock I, the main line runs to within a foot or two of the entrance (much closer, in fact, than the log we used to tie off to years ago). It is inconceivable that, in clear water, any diver could come to the end of the gold line and not be able to find his way out of the cave. Yet how many times have you seen this exit clogged with primary reels?

This last example points out an aspect of reel running few cave divers (and instructors) consider: The damage that running a reel causes to the environment.

Every time a diver runs a reel, no matter how carefully, some amount of environmental damage occurs.

Although this damage is minimal, its effect is cumulative. Given sufficient time and hundreds of dive teams, its impact can be significant.

All of us who have been doing this for a while remember favorite tie offs that have been broken or worn away through use.

Obviously, when the choice is between diver safety and the environment, safety must take precedence. However, when running a reel has no bearing on diver safety (and, in fact, may increase the risk of entanglement to others), doing so out of force of habit is unconscionable.

That having been said, we certainly don’t want to discourage divers from running primary reels when they feel that doing so is essential for safety. They just need to think more carefully about where they make their primary tie offs.

Case in point: When entering Devil’s Ear, is there anything wrong with waiting until after you get just inside the cave entrance and out of the flow to tie off your reel? Is there any way you could get back to this point and, given daylight and clear water, not make it out of the cave? Imagine not only how much easier and more convenient this would be for you, but also how much less risk of entanglement doing so would pose to both yourself and others.

The “Safe Exit” Concept

Some time ago, both NSS-CDS and IANTD realized that a dogmatic “continuous guideline to open water” philosophy was unrealistic in light of what we have learned about specific caves over the decades (not to mention the shear number of teams who may enter a cave at any given time). Thus, the standard was changed to a continuous guideline to a safe exit.

However, as I mentioned at the beginning of this article, you would be hard pressed to find a clear definition of what a “safe exit” is.

Just after last year’s DEMA Show, I was discussing this situation with Karl Shreeves from PADI. (For those of you who don’t know, Karl is one of the driving forces behind PADI’s Tec/Rec program and one helluva good cave diver.) Karl made an observation that I think brings the definition of a safe exit into crystal clarity.

“We all subscribe to the No Lights rule…right? Thus, when we return to the daylight zone and find a recreational diver swimming around without a light, no one gets particularly excited. Certainly if it is safe enough for the recreational diver to be there without a guideline, it should be sufficiently safe for us to do the same.”

So, in other words, continuous guideline to a safe exit can also be construed as a continuous guideline to the No Lights zone. That works for me. Let’s see what happens when you apply this principle to real-world dive sites. (Note that the following examples assume daylight hours, clear water — and no possibility of the basin suddenly going tannic.)

To start, the ends of the gold lines at Peacock I clearly constitute safe exits. (And, when the basin goes dark, someone always extends the line to the stairs anyway.)

At Madison Blue, there is nowhere you can go from the end of the gold line except out. (Just make sure the river isn’t rising as you enter.)

At Little River and Devil’s Ear, whether or not the end of the gold lines constitute safe exits is subject to debate, and may depend on the experience level of individual team members. One thing is for certain, however: Tying off a primary reel just inside the entrance poses less overall risk to other dive teams than doing so in open water.

In any event, that’s my take on the situation. What’s yours? I’d like to see comments from other instructors. (PS: Please sign your name to your comment, so we all know who it is coming from.)

Disclaimer: The opinions expressed in this article do not reflect the position of any agency or other individual and are intended solely to stimulate further discussion,