How to answer "what is your highest certification level"?

[boulderjohn]

In reality, if you have tables on you, and dive with a depth gauge and watch, you use the deepest dive depth and the time accrued, which give a nice safety factor. This can be done for multiple dives too, just follow the NAUI Tables (see the above post) around again, with the residual dive times shown and factored into the next dive.

OK, here are the two dives I did in Cozumel on June 23. Track them on your NAUI tables and tell me how they work out for you.

First dive: Maximum depth = 126 feet. Total dive time = 83 minutes.
Surface Interval: 1:16
Second Dive: Maximum depthy = 88 feet. Total dive time = 92 minutes

I am sure you know better, but when I see a people say they use the NAUI tables, what I frequently find is that they follow the NAUI first dive limits, do the same surface interval as everyone else, and then follow the NAUI first dive limits again.

Of course, I don't know how you can compute the second dive since you can't do the first one on the NAUI tables. Unless I am misreading it, the NAUI maximum time for a first dive with a max depth of 126 feet is 8 minutes, not 83.

EDIT: I forgot to mention that I was using 32% nitrox for both dives.

 

[John C. Ratliff]

OK, here are the two dives I did in Cozumel on June 23. Track them on your NAUI tables and tell me how they work out for you.

First dive: Maximum depth = 126 feet. Total dive time = 83 minutes.
Surface Interval: 1:16
Second Dive: Maximum depthy = 88 feet. Total dive time = 92 minutes

I am sure you know better, but when I see a people say they use the NAUI tables, what I frequently find is that they follow the NAUI first dive limits, do the same surface interval as everyone else, and then follow the NAUI first dive limits again.

Of course, I don't know how you can compute the second dive since you can't do the first one on the NAUI tables. Unless I am misreading it, the NAUI maximum time for a first dive with a max depth of 126 feet is 8 minutes, not 83.

EDIT: I forgot to mention that I was using 32% nitrox for both dives.

As you know, the NDL for 130 feet is 8 minutes. Apparently, if you did not accrue decompression time, you bounced to 128 feet then on your first dive was at multi-levels for quite some time. Do you have a graph of that dive? ‘Same for your second dive. 88 feet for 92 minutes is, with table use, a 90 foot dive for 92 minutes. That also is not a no-decompression dive. So these multi-level computers do have a lot of leeway to them. The computers will let you do a lot of things the tables won’t, but at the same time a diver can dive the tables and have very satisfying dives too. How do I know? Well, that’s how we all dived in the 1960s through the 1980s. Dive planning was much more critical in the earlier days before computers.

Use of nitrox is an entirely different situation, and these tables assumed the diver was breathing compressed air.

SeaRat

 

[boulderjohn]

. That also is not a no-decompression dive. So these multi-level computers do have a lot of leeway to them. The computers will let you do a lot of things the tables won’t,

That's the point, and that's why the dive operator requires computers. Think what a mess it would be if most of the group is diving for about 1.5 hours and one or two people have to head for the surface after 10 minutes or so.

BTW, both dives were NDL dives.

Well, that’s how we all dived in the 1960s through the 1980s. Dive planning was much more critical in the earlier days before computers.

You may have found them quite satisfying, but other people back then were not so happy with short bottom times and long surface intervals. One person was so dissatisfied that he talked PADI into researching other ways to do it. The result was both the RDP, which dramatically shortened surface intervals, and the wheel, a table that allowed for multi-level dive planning. Unfortunately for them, the wheel came out at roughly the same time as computers, and people much preferred the computers.

I really enjoyed those two dives, and I would not have been nearly as happy diving for only a tiny fraction of that time.

 

[boulderjohn]

Use of nitrox is an entirely different situation, and these tables assumed the diver was breathing compressed air.

Yes, I know, and my estimate off the top of my head is that using nitrox on a dive like the first one using NAUI tables would give you maybe 15 minutes bottom time instead of only 8.

My times were also total dive times, not tradtional, table-based bottom times, which are really meaningless with computers. So to be fair, let's estimate your total bottom time with nitrox. On that dive, we were only briefly at 126 feet (seconds, really) and began a slow ascent through a maze of swim-throughs. Once you ended your bottom time at 15 minutes, you would have ascended from that bottom to about 60 feet, so let's give you 2 minutes to reach safety stop depth, followed by a 3 minute safety stop. So your total dive time for that dive would have been about 20-21 minutes.

That would still have you bobbing on the boat for more than an hour before the computer divers reached the surface.

 

[John C. Ratliff]

Just so you guys will know, I'm not against computers; I have kids that are in the high tech industries that make these possible. I'm just curious about how the boat operators would react to an old-time diver? Since the dive watch/depth gauge/dive tables days, we've flown to the moon, developed wonderful new technologies (I'm typing on an iMac), and these are enabling us to do things that fifty years ago would have been beyond the thought process of those divers. So thank you for answering, and giving me more insights into where diving is right now with dive computers.

I have not done any dive travel, and mostly dive locally. The crawdad photo below was taken in the Tualatin River last October (2022) using a Canon F-1N camera, FD-50mm F-3.5 macro lens and in an Ikelite housing. This is a film camera. I do have digital cameras too, but thought I'd show the ol' style photography. My diving is mostly in rivers to observe the aquatic life, and I've seen a lot, from the spawning of lampreys to a salmon die-off because of high water temperatures. I dive at less than 25 feet (about 8 meters) for as long as I want, a half-hour to an hour (depending upon locations) from my home.

I have one more observation from this discussion, and that is that dive travel has really sparked innovation in the dive industry, from lighter, better breathing regulators to the dive computer, which enhances the enjoyment of diving for many, many people.

SeaRat

 

[PBcatfish]

Here is my original certification card, by Roy France in 1963, LA County. I wonder if I went onto a boat, and showed this card, whether they would honor it? Also, if I was diving my older regulator with a SPG, and they asked for a computer, and I showed them my NAUI Dive Tables, my watch and depth gauge, would they honor that? I got that original card after having been diving since 1959, after training that involved Red Cross Lifeguard/Swimming Instructor certification, and years on my North Salem High School Swim Team. I had also read J.Y. Cousteau's The Silent World three times. If you read that book, you'll have most of the academic background necessary for diving.

I have other certifications; just trying to see if I ever do a boat dive, what I would need.

SeaRat

PS, our Salem (Oregon) Junior Aqua Club had to import Roy France from California to Salem to get certified, as there were no instructors in our area at the time.

Your old regulator has an SPG??? My second oldest one has a pin gauge & my oldest one has no gauge at all (from back in the J-valve days).

That aside, I've had commercial boats let me dive with an SPG & a watch before. That seems to vary from boat to boat & sometimes changes a little depending on where they are dropping you in. If it's a hard bottom location in less than 35 feet of water, they may not even care if you bring the watch. If it's a place that's 100' deep with 80' of vis & 3 knots of current, where people frequently hover at 30' while drifting with a spear gun, until they see a fish, then drop down to shoot it, then go back to hover level to look for the next fish, then the computer is going to be necessary.

 

[RTee]

Your old regulator has an SPG??? My second oldest one has a pin gauge & my oldest one has no gauge at all (from back in the J-valve days).

1978...the first reg I purchased following my NAUI Scuba diver certification was a Healthways. Only one regulator attached to the first stage...that's it. An advanced set-up would have a depth gauge (which I did not have). Small plastic backpack with straps mounted on a 72 cft steel tank with J valve (400 psi reserve if I remember correctly) and using a horse collar that you could only be inflated, under control, orally, for buoyancy control. Alternatively you could pull the co2 cartridge tab.

With such set-up, buddy breathing became a regular training exercise at the pool.

We've come a long way.

 

[Pearlman]

Didn’t read the whole thread (it’s too long) so pardon me if the question is a repeat or already covered.

To the divers in America - would you disclose that you already had a Rescue Cert or just stick to writing down AOW due to the risk of being sued in case of a fatal accident?

 

[Wibble]

To the divers in America - would you disclose that you already had a Rescue Cert or just stick to writing down AOW due to the risk of being sued in case of a fatal accident?

Did you mean divers in Malta?

 

[MichaelMc]

To the divers in America - would you disclose that you already had a Rescue Cert or just stick to writing down AOW due to the risk of being sued in case of a fatal accident?

I would just show a Deep or AOW. The boat should be happier with my having rescue, as it means more folks on board are likely more squared away on incident prevention, but it likely does not impact the dives I can do with them. No big reason not to show the Rescue though, but it does not 'clear' me 130' while the deep does. In the US!

But I may not be the best example as my rescue cert was part of my Scientific diver cert, which is not a card you hand people type thing but a letter of qualification sent between research institutions.

When diving in the US, dive professionals can have a "duty of care" to someone. But it involves conditions such as 1) being a dive pro, and 2) being paid to instruct or assist them at that time. If they are negligent in that duty of care and something happens opens them to liability. So dive pros start their day with part of that satisfied, thus one step closer to an issue of liability. Non-pro divers very clearly do not start their day as pros, no matter what non-pro worlds-best-diver cards they have or show. In the US!! In other countries, who knows???? (I'm not a lawyer.)