What computers are you using for tech dives?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

The fashionable thing on here is to do AN/DP and then dive a twinset with a deco stage. That is a very big jump from typical single cylinder NDL diving and a fair old jump from NDL twinset diving.

I think doing AN/DP before having some experience/training in twin cylinder configurations is a bad idea. While I can't speak for other instructors, I place a huge emphasis on situational awareness and buoyancy in an AN/DP course, to the point where I have been known to stop a class and ask a student to come back later to complete it. If you can't hold a stop, or you're so flustered from the doo-dads dangling off you that you are oblivious to your surrounding, you shouldn't be taking AN/DP.
 
I think doing AN/DP before having some experience/training in twin cylinder configurations is a bad idea. While I can't speak for other instructors, I place a huge emphasis on situational awareness and buoyancy in an AN/DP course, to the point where I have been known to stop a class and ask a student to come back later to complete it. If you can't hold a stop, or you're so flustered from the doo-dads dangling off you that you are oblivious to your surrounding, you shouldn't be taking AN/DP.
This is kinda my way of thinking.... get the buoyancy down as well as other new skills that come with diving doubles. Before I get into AN/DP at least that way I can more ability to focus on new tasks as they come not everything at once. But, I am trying to keep an open mind and an eye on the future to ensure I am learning, training and purchasing the right gear. For example when I was buying my pony set up, I was told to get a 40cf rather then a 30cf by a few people. Because, as I got into tech the 40cf is what I would need for deco bottles. Well I had no plans at the time to get into tech diving. Now I am used to carrying a sling pony, but now I have to buy 40cf deco bottles. The 30cf won't work....
 
This is kinda my way of thinking.... get the buoyancy down as well as other new skills that come with diving doubles. Before I get into AN/DP at least that way I can more ability to focus on new tasks as they come not everything at once. But, I am trying to keep an open mind and an eye on the future to ensure I am learning, training and purchasing the right gear.

This sport gets expensive quick, and sadly there's a bunch of misinformation on gear from people that don't really have a lot of technical diving experience. Example, the entire sidemount craze -- I'm a firm believer in starting with a basic backmounted twin cylinder configuration as the basis for technical diving and then moving to sidemount or CCR if you find you are doing dives that need those tools.

In seeking out instructors, I'd start with asking yourself what kind of diving really gets you cranked. 300' wall dives? Crawling through tight places? Mile long cave penetrations? Deep shipwrecks? And then finding guys that do that kind of diving regularly, not guys that just talk about it. Check references, ask to see computer downloads or logbooks, and be picky with who you train with.
 
Example, the entire sidemount craze -- I'm a firm believer in starting with a basic backmounted twin cylinder configuration as the basis for technical diving and then moving to sidemount or CCR if you find you are doing dives that need those tools.
In my experience, the biggest obstacle to student success in early tech training is the valve shutdown drill. Students find it very hard to go through that drill in backmounted doubles while maintaining their position in the water column. People who look at the total number of dives required for a certification sometimes forget that you have to do the skills successfully on those dives, and you aren't going to get a certification if you can't do a satisfactory valve shutdown drill each time the standards call for it.

But what about sidemount?

Well, if you do the class in sidemount, this is no longer much of an obstacle. You still have to do the valve shutdown drill--many times with some agencies--but the skill is much easier when the valves are by your armpits rather than behind your neck. You also do not have a manifold to deal with. I have never had a sidemount student have a problem with this drill.

The diver who gets certified in sidemount gets the same certification as the backmounted diver. The backmounted student who later decides to go sidemount will have no trouble shutting down the sidemount valves in an emergency. The sidemounted student who someday decides to dive backmount may have a very bad day if he or she needs to shut down a backmounted valve in an emergency. I have had to shut down a backmounted valve a couple of times in my diving, and each time I was very glad my training allowed me to do it.
 
There were a couple of people taking TEC40 the same week as me who did not familiarize themselves with the different buoyancy and trim characteristics of using backmounted doubles prior to the class. All of them had more difficulty, then they should have. I thought this was going to be an issue before hand, so I dove for 2 months with doubles before the course. This allowed me to get my weighting, weight distribution, and trim down well before the class. I also started back kicking which I also knew I was going to have an issue with.

I did hold off on learning the valve drills as I did not want to learn them differently then how I was going to be instructed. Sure enough, the three tec instructors that I have taken classes from / with all did the valve drills slightly differently. In each case, I was asked, why I did the valve drill that way. So, if you do decide to learn the valve drills, be prepared to do some explaining and possibly changing how you do it.

Another good thing to do is to figure out how whatever computer you have works for timing deco stops and gas switches.
 
Last edited:
In each case, I was asked, why I did the valve drill that way. So, if you do decide to learn the valve drills, be prepared to do some explaining and possibly changing how you do it.
And realize that the sequence and the way they want it done applies only to the class and does not matter in the real world. The valve drill's purpose is to make sure you can reach the valves and handle them without losing control of your position in the water. You will never actually do it in an emergency. In a real emergency, you only to the segments of the drill that are necessary to solve the problem. You never do the whole thing.
 
Cyborg , congrats. Like computers, you'll have a kid, and a backup kid lol. I have two.

That said, I'm in your same spot and I'm teaching my self discipline to cut tables and follow them.

I am doing simulated deco by donning my doubles diving under ndl and following arbitrary profile of ascent. Depth and time depth and time.
 
http://cavediveflorida.com/Rum_House.htm

Back
Top Bottom