Diving watches

[yle]

Perhaps there's different considerations if you're a DM somewhere and your backup is there specifically to finish a dive for paying customers. My cave diving buddies with 3 or 4 lights abort no questions asked if 1 fails.

I think you hit the nail on the head here: assessing how vital the equipment is to continuing the dive. In the case of your cave divers, lights are absolutely essential. So a failure means the dive should be aborted.

It seems that there's some disagreement as to whether or not a dive computer is absolutely essential for all dives, and perhaps this is where the dividing line lies: my scenario above, a shallow dive for which the DC would only be used for time and an NDL that exceeds my air... maybe the DC is not essential. But certainly a deeper dive the DC would be more relevant.

 

[Diver With Altitude]

The dive is OVER if your dive computer fails and you don't have a back on you, NO WAY should you continue the dive at all.

Sorry, but THIS is nonsense. I learned to dive before computers were the norm. If my computer fails, I’m diving the tables using my watch and SPG. if either of those fail, then the dive is over. If the computer fails after the time designated in the tables, then I make an immediate, but leisurely ascent, as I know my NDL will increase significantly as I ascend.

 

[BoltSnap]

Many experienced divers are more flexible than that, this strategy would have little to no risk.

I'd rather go with well known established diver training agencies, computer manufacturers, DAN and other entities that are identifiable and accountable than by "experienced divers" who are nameless, faceless and unidentifiable persons we can't ascertain their knowledge or training or experience.

The rules set by the agencies mentioned don't leave much room for interpretation or extrapolation. When it comes to my health and my spinal cord or the health and safety of my friends, students and all those I know, I rather go with the experts than anonymous "experienced divers" on the internet. It will be a terrible disservice and violation of standards for me as an instructor to come and disregard all of the known experts and place my safety and the safety of my students and those that I care for on what these unknown people say. it is not prudent to do this to say the least in this context here.

Anyone is free to do what they want with their bodies and their health, I can't police them but I don't go with their "advice" or recommend it to anyone.

 

[BoltSnap]

Sorry, but THIS is nonsense. I learned to dive before computers were the norm. If my computer fails, I’m diving the tables using my watch and SPG. if either of those fail, then the dive is over. If the computer fails after the time designated in the tables, then I make an immediate, but leisurely ascent, as I know my NDL will increase significantly as I ascend.

I learned to dive many, many years before dive computers came out, in their current form, and I used the US Navy dive tables before I bought my first dive computer in 1987. If my dive computer fails during the dive and I don't have a back up dive computer with me, which is rare, I am ending the dive and making as slow ascent as I can with precautionary stop and go to the surface and that will be it for diving for 24 hours before I can go back to the water with dive tables or a fresh dive computer.

This is what the experts in all levels and all agencies including the dive computer manufacturers say and make it a standard. I won't go against that.

You do what you want, it is your spinal cord and your health not mine.

 

[BoltSnap]

im not sure what you expect from an industry turning out divers taught not to think and to "just follow the computer"

Perhaps that is your experience in your training but it isn't my experience at all. I teach decompression theory and explain the various terms as they relate to dive tables and dive computers. The agency I use, NAUI, has sections in their textbook and eLearning material regarding dive tables, dive computers and principals of deco theory.

 

[Diver With Altitude]

You do what you want, it is your spinal cord and your health

Since the scenarios I’ve described are more conservative than a computer-guided profile, there is no issue with increased risk. Diving with a watch and SPG as backup to a computer is safer than diving with only a single computer.

 

[BoltSnap]

Diving with a watch and SPG as backup to a computer is safer than diving with only a single computer.

No, not really. Again when you dive with dive computer, tables are irrelevant until after 24 hours of outgassing. The safe and prudent thing to do is to have a backup dive computer. I don't understand why you insist on a "dive watch" where a basic backup dive computer is usually less cost than a "dive watch."

 

[M-Cameron]

No, not really. Again when you dive with dive computer, tables are irrelevant until after 24 hours of outgassing.

not really so long as you are still within the NDL for your max depth according to the table.....diving a square profile is always going to count against your time as you arent being reimbursed for time at shallower depth....

so if you are diving at multiple depths, it is not any more dangerous to switch back to diving under a square profile should you need to.

 

[Diver With Altitude]

No, not really. Again when you dive with dive computer, tables are irrelevant until after 24 hours of outgassing. The safe and prudent thing to do is to have a backup dive computer. I don't understand why you insist on a "dive watch" where a basic backup dive computer is usually less cost than a "dive watch."

The point is, the tables are more conservative. The whole reason computers were developed was to increase bottom time.

 

[BoltSnap]

not really so long as you are still within the NDL for your max depth according to the table.....diving a square profile is always going to count against your time as you arent being reimbursed for time at shallower depth....

so if you are diving at multiple depths, it is not any more dangerous to switch back to diving under a square profile should you need to.

Again, what you are stating goes against every single dive computer manufacturers, DAN, training agency and expert out there. Your computer goes down, you stay out of the water for 24 hours before switching to a fresh dive computer or dive tables. I am not inventing the rules, I just go with the industry standards. You want to invent something on your own and convince yourself that your invention is correct that is your problem but it doesn't make it a valid invention.