Two additional NiTek X Beta units were received right before the Christmas break; just what I needed, another excuse to go diving! I managed to get several dives in; one in an unnamed sink that runs 145 ft in depth and the others in Rock Bluff, a small sidemount cave off of the Suwannee River. The X performed as planned and the new 75/95 gradient compared very favorably with the NiTek He for total deco time. The finish of the case held up well to the loose rocks that tend to fill the entrance to this spring.

More Beta units should be arriving as the new fiber optic back light becomes available in the next couple of weeks.

Jerry Murphy

Product Manager

I see many variations of the singles mounting plate on the market today. It seems every technical equipment company has something similar for adapting the hardcore doubles backplate to single tank. I’m flattered to see so many copies, but it all started with trying to make a girl happy.

In 1986, my girlfriend started diving twin 80’s for her cave class. She liked the feel of her new technical harness (that’s another story…the origin of the deluxe harness) and she also wanted to dive her tech harness with singles rather than going back to a jacket BC. I thought about how to do it. Some cave divers had cut slots into their backplate and Classic Wing in order to thread a couple of cam straps through the plate. I wanted something more finished and adaptable for the product. I knew the larger market for a SMP was to existing cave divers and not new cave divers. Experienced cave divers already had a backplate and wing and knew how to dive them, so putting a single on a sixty pound wing (not something we recommend for a new diver) would be easy for them to deal with.

Looking for a starting point I took one of our ABS backplates and trimmed it about 1 ½ inches out from the center bends and cut slots in it for cam straps. The ABS was easy to machine so I whipped out a few samples and gave them to friends and my girlfriend. They dived it, liked it and orders started coming in as divers saw the samples.

The design has not changed over the years and we see other dive manufacturers have enjoyed selling this design under their own brand name. Since the first SMP, Dive Rite has added cam strap slots to all of our backplates and wings so the SMP is no longer really needed to dive a single on a backplate. However, it looks good so some divers still prefer to use one just like I designed it in 1986 for my girlfriend. My girlfriend became my wife in 1987 and Lee Ann has made me think about women and diving ever since.

Lamar

On another note the slots in the doubles wing came before we added the slots in the backplate. The Europeans had a few methods for putting a harness/wing on doubles. One method involved a molded doubles tank boot with one doubles tank band and a manifold or independents. We supply them with extra long cam straps to attach the twin cylinders to the harness/wing combination. Today many of the Europeans use the double tank band/bolts method for attaching a harness, backplate/wing combination.

Nitek X beta unit testing is underway. I took one cave diving in Mexico last week and it worked as designed the first three days. After that the screen contrast wouldn’t hold the setting due to a software bug. Additional beta units will be in next week, pending the arrival of custom fiber optic backlighting components.

We will begin doing weekly reports on the testing.

Lamar

We have updated the GF factors for the NiTek X, specifically the CONO GF. See Phil’s comments below:

Lamar

Based on your input, we have re-worked the gradient factors and have a new GF for CONO as follows:

CON0 : GF 75/95
CON1 : GF 40/100
CON2 : GF 30/75

Briefly. CON2 is Eric Baker’s conservative base assumption, “if you want conservative, use this”. CON1 is good low GF but no surface penalty over an above the deep stop time “this gives considerable deep stops but does not extend shallow deco too much”, CON0 base level safety “Some movement of shallow stops deeper to hint at deep stops, for recreational use”.

I labored most over CON0. Use the Workbench to try these profiles. You will notice that 75/95 has the characteristic that for serious or less serious recreational dives the deco is hardly longer, but does move one or two stops deeper in the water and spread the deco over a deeper range. It is more conservative by “deep stop” rules for this reason. Eg. for a 130 ft dive that usually yields a Buhlmann deco starting with one minute at 9M you will see a few minutes at 12M followed by a slightly longer deco, total. This happens because you need to stop earlier because of the LO-GF, but you are not on-gassing still (much) because you are shallow enough. So the deco is actually more graceful by the same “deep stop rules”. It is more complicated than that physiologically, but as far as the model maps to this I think we are in bounds.

Phil

The O2ptima manual needs a few updates. We have been working on a few items to add before making the next revision.

These include:

1. The new Delrin HH are easy to use and have some firmware updates added, including a battery indicator.
2. The premix rod was to be taken out of the unit, but I found that on rapid descents the premix rod is advantageous. I assumed instructors would address this until we got a new revision of the manual out. We use a new connector to help with alignment and it is easy to remove when servicing the head. The grommet should be at the base above the sensor disk so the EAC pushes against it to seal against CO2 bypass. I do not recommend putting it on top as it will surely get lost during assembly.
3. The new quick release elbow for the premix rod has a flow restrictor to maintain a constant flow from solenoid and adjust for variations in the solenoid orifice.
4. New accessories include an inline solenoid shutoff.

We are gathering the Micropore test data and will soon post it. I realize there are some questions since the release of the CE comparison test data just before DEMA. We have reviewed it the test data. Dive Rite is not a European company so we didn’t build the O2ptima to CE specifications. We built a CCR around new technology and based our performance on US Navy standards, something a little closer to home. We were able to build a smaller, more efficient unit than our competitors.Now that we have built a CCR on a unique platform we will start modifications to go for CE approval. The problem is that CE standards are written for older technology, but if CE standards are not updated, we will evaluate the necessary changes to meet the CE directives.

If you want to know about the performance of the O2ptima, just ask the divers using it. I am always available for a dive when you visit North Florida. You dive your unit and I will dive the O2ptima.

Lamar

I finally got a chance to go side mount diving after DEMA. Jerry Murphy, our Product Manager, and I did Rock Bluff and had to dig the entrance out just to get in. I felt this would be a good test for the JetStream Regulator. I wanted a regulator that I could breathe from the left side without running it around my neck when side mounting. The JetStream worked very well. It secures to the left shoulder with a bungee strap around the webbing to keep it high and out of silt. I had our new regulator necklace (debuted at DEMA) on the right side regulator. The adjustable regulator necklace let me pull it up tight for side mount…a little tighter than most divers would wear a regulator for back mounted cylinders.

Observations

1. Both regulators – I had to dig some small rocks out of the first stage caps - yeah it was very tight.
2. The necklace works just as designed, but I am having the manufacturer change the crimps before production is released so it will be another 30 days before we have stock.
3. Nomad bottle placement is good with the new chokers on the necks. This was my first chance to use them in a small restriction situation. I had tested them, but had not had the chance to test the tank placement with chokers in a tight body squeeze.

I routed the Jetstream second stage hose downward in order to make the standard 28-inch hose length lie flat. It pulls up easily for use.

Lamar

The Nomad is working well for people who want to sidemount. Over the past few months I have taught a few classes; both sidemount and CCR. One of the common problems I began seeing is getting the bungee routed through the regulator, around the tank neck and then clipped to the harness. It can be a pain to hold up the tank, while stretching the bungee enough to get it attached. The easy way to use it is to leave it clipped to the harness and just pull it over the cylinder neck. This appears to work, but depending on your attitude in the water the cylinder may slip out of the bungee. As I thought about this while watching a few students struggle and I remembered my problems diving out of a Zodiac on the Black Sea in Russia this summer. Sometimes the neck connection can be a real pain. The bottle needs to float under the arm to find the sweet spot for sidemount position, but there should be a secure and easy connection to keep the bottle in place.

After a few test dives I introduced my students to a new way to secure the neck of the cylinder in the bungee with 100% satisfaction from the divers. It’s very simple, use a standard stage strap with XL bolt snaps on the bottle. You need the XL snap because you are going to clip into the bungee. We have added a choker to the neck of the cylinder. It holds the top clip up against the neck of the bottle. We make the chokers but you can make one out of line as well. The key is to have the gate of the snap against the cylinder neck. I like the chokers because they are adjustable so they can work with your sidemount setup and or be loosened if you use the cylinder as a stage bottle.

The point is now you clip into the bungee rather than wrapping the bungee around the cylinder neck. The bungee needs to be 4” shorter than what you would normally use. I used to use the 17” bungee and I had to shorten it to 13”. Now it is easy to clip in and keep bottles side mounted for CCR bailout or 95’s on a sidemount dive.

So to see if anybody is actually reading my blog, I will ask interested divers to call Dive Rite and tell the guys you want the latest sidemount modification for your Nomad, you want the chokers. Send back your straps and we will shorten them and give you the chokers free of charge. I want people to enjoy it as much as I do.

Lamar

Today I am writing about fins after overhearing a diver at one of our Tech Tours complain that the Dive Rite fin is too heavy, and walked away with her split fins in her hand. I thought about her comment and realized the problem. Most divers are looking for what is easy, rather than what is efficient. Efficiency is the cornerstones of cave diving training; the average diver cannot appreciate the discipline cave divers use, yet it is the premise for all technical diving disciplines.

I was a test diver for the original split fin, the Apollo Bio fin. They completed their test in recreational environments and I got to play with them in the caves of North Florida. I was not impressed. The split fin is designed to give the diver forward propulsion with the least amount of directed effort. Essentially, this means wasted energy and still there are results. The split fin is designed for the diver doing a modified flutter kick and nothing else, which is the kick used by newly certified divers. Instructors spend hours teaching new divers not to bicycle kick because it is inefficient. The split fin takes advantage of the bicycle kick mentality, giving divers a method of inefficient kicking, yet still with some movement forward.

During our testing of split fins and our fins, divers using split fins could not maintain the pace set by average cave divers. One test diver suffered severe cramps using split fins in an attempt to maintain a normal pace for a dive he had done many times before. Split fins can propel an open water diver with a single cylinder through the water to the divers satisfaction, but it is out-classed in technical dive environments. For technical diving, the diver needs a fin that can perform in various conditions including high flow, tight areas and moving mass thru the water. A technical diver needs a fin that is an extension of the foot for complete control and application of various technical fining techniques such as, modified flutter, frog, shuffle kick and ceiling walk. A split fin just can’t compare. Whenever you increase the mass of a diver from single cylinder to doubles, side mount or staging the split fin does not measure up.

Why did I buy the molds for the Apollo Prestige Fin? We bought the molds for the fins in 2001 because I believed they were the best fins on the market. I dived it for two years and was very impressed with the performance-to-weight ratio of the fin. It actually looks like the old Farallon fin with the rounded blade that was considered the best fin on the market in its day. I owned three pair of them, but it took an above-average diver to take advantage of the power you could extract from the fin. For cave divers battling upstream in caves with outflows of 1 to 2 knots you needed every advantage you could get.

The Dive Rite fin is designed with two materials, a plastic and rubber combination to give it strength and flexibility in water. Instead of venting the middle we have a flexible rubber insert to utilize the thrust in every stroke. We don’t believe in wasting any movement the diver may take with his fins. The blade design captures any nuance the diver may use in propulsion techniques. This lets the diver use every ounce of energy he (she) expends with a kick. This is very important to the tech diver pushing one to two miles against current. Split fins can’t capitalize on the various fin kicks to decrease fatigue and cramping like a single blade fin. Our fin is not for everyone. If you can’t swim or run a mile then stick with the split fin, but if you don’t want to waste your energy then use a fin designed to take advantage of the effort you put into the swim.

I know some may disagree because you own split fins, but facts are facts. If you question my conclusions then send me an email and join me for a dive.

Lamar

The programming to add more dive log memory has been completed as well as the fourth cell pin compatibility for the Fischer connector. Circuit boards for the Beta units are scheduled for October 9^th at the PCB house, meaning we should have our beta units by mid-October.

Decompression software is in the works and a demo version will be available soon. We will post the demo version on our website as soon as it is ready.

Lamar

We have listened to requests for more logbook memory and compatible cabling for 4^th cell CCR integration. All these things are a go, but delayed the production beta units. We had to give up our slot at the PCB production house to address the new hardware features. As soon as we can get back on the schedule at the PCB house we are days away from production beta units.

Lamar