What happens in a recreational computer if you go past the NDLs?

[Bob DBF]

Sorry - not buying it. Pretty certain that the manual for your (every) computer is on-line at the manufacturer's website. No excuse.

I'll second that and add that a reading on a regular basis is handy because if you don't see a message regularly you will forget what it is when it is seen.

My embarrassing dive was getting on the surface and seeing deco flashing on the computer. I never saw the computer in deco during the dive, or any unusual reading at all on the dive. I told my buddy and we dropped to the safety stop, the computer read completely normal but we decided to stay untill about empty on our tanks.

Come to find out, the computer flashes deco to remind you that you were in deco on the dive. It seems on the swim up from depth there is a long flat spot on the upslope and at that area on the downloaded graph I had gone in and out of deco for less than a minute without my notice. Since I didn't need a ceiling imposed after I was out of deco, the display looked normal to me, until I surfaced.

A good laugh was had by all, at my expense of course.


Bob

 

[hhmoore]

If you are talking about the Aqualung i300, mentioned in another post, you can find the manual here: http://www.aqualung.com/us/technical_library/i300_owners_manual_EN.pdf

That's the one. I did subsequently find that page; but I appreciate the link...it would probably be worth reviewing again, since a) about a year has passed, and b) I've got a bit more diving experience, so I'll likely understand some of the functions better.

I can only speak for PADI on this issue.

About 6-7 f years ago (not sure), PADI introduced a computer version of the OW course. It does cover this. It tells you that a dive computer will give you directions to descend if you accidentally exceed your NDLs. It tells you to learn how your specific computer does this.

I did my open water course through a PADI shop last summer, and there was little more than a mention of computers. We didn't have them for class; so I suppose there wasn't much point in talking about them. We didn't discuss/use the eRDP until our open water dives (other than being told to familiarize ourselves with them, and possibly using them for the later modules in the elearning)

 

[MargaritaMike]

I was recently on a dive boat where a couple were in the dive group. They represented themselves a relatively new diver (less than 25 dives) and an experienced diver who had done most of his 100+ dives 10 years ago. After the first dive the "experienced" diver said (when asked about his constantly beeping computer) that his computer told him to do a deep stop and after he cleared the stop he went back down. He said he got a second deep stop and cleared it and then he was getting low on air so he came up. The thuds that were heard were 3 or 4 of our jaws dropping to the deck. All I could say was "you did WHAT?" On the second dive we had a lion fish hunter who was identified in the briefing as a solo diver and NOT to follow him. The newbee went down to about 110+ feet (I was at 95 and they were below me) and was finning and dumping their BCD to get deeper. It looked like they were interested in what the LF hunter was doing (he was around 120' or so). Eventually they came up but skipped the deco stop their computer gave them because they didn't have enough air. They got on board and told everyone what they did and wanted to know why their computer was locked. They said they had a twilight dive scheduled and wanted to know if it would be okay if they didn't go very deep. Again, you could hear the jaws dropping.
To me, not only should they have read the manual, they should have also read the PADI, NAUI, etc. OW manual about diving deep, NDL, and decompression. I didn't hear about either one of them in the chamber, so I guess they dodged the bullet.

Cheers -

 

[boulderjohn]

I did my open water course through a PADI shop last summer, and there was little more than a mention of computers. We didn't have them for class; so I suppose there wasn't much point in talking about them. We didn't discuss/use the eRDP until our open water dives (other than being told to familiarize ourselves with them, and possibly using them for the later modules in the elearning)

What you appear to be saying is they did the table version of the course without doing the tables.

How did you do the final exam? If you did the table version of the course, there is a long session on using the eRDPml to plan dives. If you did the computer version, there is an equally long section on using computers. If you did neither in class, I don't see how you could pass the exam.

 

[TrimixToo]

Just read the effing manual.

Where I work, we have a time-honored abbreviation for that: RTFM. (The "F," of course, stands for "fine" or "fabulous" in a family setting.) ;-)

 

[hroark2112]

Most recreational computers will say they are not to be used for decompression diving, but if you do go into deco it will give you the stops it deems appropriate to get you out of the water safely.

These times can be significant, way longer than anything a tech computer will give you. Almost as if they are intended to punish you for going into deco and to remind you not to do it again!

 

[hhmoore]

What you appear to be saying is they did the table version of the course without doing the tables.

How did you do the final exam? If you did the table version of the course, there is a long session on using the eRDPml to plan dives. If you did the computer version, there is an equally long section on using computers. If you did neither in class, I don't see how you could pass the exam.

As I said, the only mentions of the eRDPml prior to the check off dives were telling us to familiarize ourselves with it - that we would have to use later. For the chapters in the e-learning & exam, I used tables or eRDPml (I found having to restart the eRDPml for each calculation to be tedious - during the open water portion, one of the instructors observed me & said I shouldn't have to do that...but he wasn't able to it any other way, either).

 

[ATJ]

One of the things that annoys me about both my Oceanic Atom 3.0 and Garmin Descent Mk1 is how they handle exceeding NDL.

If you don't exceed NDL they will want you to do a 5 or 3 minute safety stop respectively. A few times I have slightly exceeded my NDL with the Oceanic and once with the Garmin. They both initially gave me a required deco stop but as I was ascending slowly anyway, that was cleared before I got to 5 metres. i.e. they said I no longer had a deco stop obligation. However, the safety stop was cancelled. i.e. both computers didn't suggest I needed a safety stop. That seems crazy to me.

My Shearwater Perdix still expects me to do a 5 minute safety stop (as opposed to the normal 3 minutes) if I exceeded my NDL but subsequently cleared it.

 

[Saniflush]

As I said, the only mentions of the eRDPml prior to the check off dives were telling us to familiarize ourselves with it - that we would have to use later. For the chapters in the e-learning & exam, I used tables or eRDPml (I found having to restart the eRDPml for each calculation to be tedious - during the open water portion, one of the instructors observed me & said I shouldn't have to do that...but he wasn't able to it any other way, either).

When I was first learning how to operate it I was having the same problem and then I read the manual http://elearning.padi.com/company0/tools/eRDPML_InsforUse.pdf and watched some youtube videos. It was not very intuitive to me for some reason. I would also contend that if everyone had to learn the tables initially then LDS would sell a lot more computers.

 

[tarponchik]

Sorry - not buying it. Pretty certain that the manual for your (every) computer is on-line at the manufacturer's website. No excuse.

My comp's manual (Cressi Archemede II) explains this on pp 179-180. However, the resolution of figures in the manual is so low you won't understand a damn thing looking at Fig. 20 on p. 198. Even with zooming in, I can see the DECO warning and the numbers, but except for the TOTAL (time added) I can't tell which of the recommended DECO profile number is which.