Diving watches

[Thombalabomba]

Well, of course if your only instrument fails, you’re going to abort, but that’s not what we’ve been discussing here. All this time, you’ve been saying that if your primary fails, you abort, but now you say that on rec dives, you don’t even use a backup. Losing a primary on a tec dive is a completely different discussion.

Indeed so i think i'm being consistent in that if my primary fails i abort?

If i go to bonaire and do warm water shore dives to 15m-20m inside the bay i won't bring a backup.
If i am in the north sea at 35m with low vis, low temp and heavy current i will bring a backup. I will bring other backup pieces of equipment as well that suit the situation. My backup equipment is what i need to cancel the dive from any point in the dive with a reasonably high margin of safety. Both dives can easily be considered rec dives if performed within NDL limits with no penetration etc.

The whole point is that this is all planned before going into the water. In either case i would abort the dive if the primary fails. My plan is now dead, i am not switching plans during the dive. I will run contingencies that are part of the original plan.

It still strikes me as a strange discussion since i know of exactly 0 hazardous/extreme/material heavy hobby's where it is common practice to follow the original plan on backup equipment, only to get home safe. I also know of 0 organisations or instructors that teach this, whether it's skydiving, parasailing, scuba diving, spelunking or flying aircraft.

I am not sure why it's so essential to not abort a dive when something happens that most likely will never ever happen to you during your entire diving career.

Also i've never had or heard of a dc failing during a dive apart from on the internet. but that's a different point.

 

[rongoodman]

Again when you dive with dive computer, tables are irrelevant until after 24 hours of outgassing.

Why 24 hours? That's the complete desaturation time for Buhlmann compartment 12. Why not use compartment 8, or 15, as the benchmark? One of the nice things about the Shearwater tissue loading graphs is being able to watch how the various compartments load and unload over the course of multiple dives and multiple days and maybe make more informed decisions instead of just quoting a rule.

 

[Diver With Altitude]

this is all planned before going into the water

i am not switching plans during the dive

This is exactly my point. I plan to the tables and I’ll stick to the plan, if all I have is a timer and SPG. If my computer is functioning, the resulting dive will be longer than I can plan for from tables (the PADI “Wheel” for multilevel planning was new when I did OW and I never trained on it ). I suspect most divers today don’t actually plan their dives beyond picking a site and then just doing whatever their computer tells them they can do. That’s not planning.

flying aircraft

To use your aviation analogy, if you’re flying in VFR conditions (VMC) and you lose your PFD, but still have an HSI and all other instruments are working, are you going to land at the nearest airport, or continue to your destination? I’m talking about diving in “VFR” conditions, not your North Sea “IFR” conditions.

 

[Doc]

….. if you’re flying in VFR conditions (VMC) and you lose your PFD, but still have an HSI and all other instruments are working, are you going to land at the nearest airport, or continue to your destination? I’m talking about diving in “VFR” conditions, not your North Sea “IFR” conditions.

YGTBFKM, IDKT

IRL:

SCNR, NBTYRSP

 

[Doc]

I suspect most divers today don’t actually plan their dives beyond picking a site and then just doing whatever their computer tells them they can do. That’s not planning.

Ahh, we have met, then. My name is Inigo Montoya. (rental BCD, Force Fins, AIR2, suicide clips, the evil anti-JJ)

 

[scubaozy]

Indeed so i think i'm being consistent in that if my primary fails i abort?

If i go to bonaire and do warm water shore dives to 15m-20m inside the bay i won't bring a backup.
If i am in the north sea at 35m with low vis, low temp and heavy current i will bring a backup. I will bring other backup pieces of equipment as well that suit the situation. My backup equipment is what i need to cancel the dive from any point in the dive with a reasonably high margin of safety. Both dives can easily be considered rec dives if performed within NDL limits with no penetration etc.

The whole point is that this is all planned before going into the water. In either case i would abort the dive if the primary fails. My plan is now dead, i am not switching plans during the dive. I will run contingencies that are part of the original plan.

It still strikes me as a strange discussion since i know of exactly 0 hazardous/extreme/material heavy hobby's where it is common practice to follow the original plan on backup equipment, only to get home safe. I also know of 0 organisations or instructors that teach this, whether it's skydiving, parasailing, scuba diving, spelunking or flying aircraft.

I am not sure why it's so essential to not abort a dive when something happens that most likely will never ever happen to you during your entire diving career.

Also i've never had or heard of a dc failing during a dive apart from on the internet. but that's a different point.

How hard is to plan a multilevel dive 35m for max ndl and then to 12m for rest? This is your back up plan then when your main computer fails. A dc is not exactly a precision instrument, it’s a risk assegment tool. if I ever take 2 dc with me, one of them will be in bottom timer mode. If you are not diving with same make or deco model, a backup will be more of an annoyance.

 

[jborg]

I suspect most divers today don’t actually plan their dives beyond picking a site and then just doing whatever their computer tells them they can do. That’s not planning.

Hey, I resemble this! For the sites I dive locally I jump in with the plan to dive until I’m cold, bored, or getting close to air or NDL limits (neither of which is likely as these are shallow sites). This seems like perfectly adequate planning for the circumstances.

I *can* do gas planning, looking up tables etc, but there’s really no need for pretty much all my diving…

(ObTopic: I love the Tudor Pelagos. It generally stays on land unless I’m just swimming or snorkelling.)

 

[Thombalabomba]

This is exactly my point. I plan to the tables and I’ll stick to the plan, if all I have is a timer and SPG. If my computer is functioning, the resulting dive will be longer than I can plan for from tables (the PADI “Wheel” for multilevel planning was new when I did OW and I never trained on it ). I suspect most divers today don’t actually plan their dives beyond picking a site and then just doing whatever their computer tells them they can do. That’s not planning.

To use your aviation analogy, if you’re flying in VFR conditions (VMC) and you lose your PFD, but still have an HSI and all other instruments are working, are you going to land at the nearest airport, or continue to your destination? I’m talking about diving in “VFR” conditions, not your North Sea “IFR” conditions.

Yeah i completely agree with the aviation analogy on a vfr flight. On ifr if i have to fly on analogue backup because the pfd fails i would try to land though, and in a steam gauge 172 i wouldn't go up in ifr conditions as a simple PPL flyer.

Anyway, i like to follow my same set of rules regardless of the dive i am doing, makes me feel like a safer diver in adverse conditions if i stick to my protocols and i've never hard to abort anyway.

 

[Thombalabomba]

How hard is to plan a multilevel dive 35m for max ndl and then to 12m for rest? This is your back up plan then when your main computer fails. A dc is not exactly a precision instrument, it’s a risk assegment tool. if I ever take 2 dc with me, one of them will be in bottom timer mode. If you are not diving with same make or deco model, a backup will be more of an annoyance.

Exactly so if i have to hang on a line a few km offshore for deco (or safety on a rec dive) in brown water with <3ft vis and no ref points i'll still thumb the dive on an equipment failure, doesnt mean i shoot up to the surface. My buddies dive in the same manner. My secondary would be in gauge mode like you said.

Anyway live and let live guys, i like the way me and the people i dive with dive. Every dive and divespot is different, let's stick to that.

I also still like watches

 

[El Diablo]

This is why I bought a dive watch. It was relatively inexpensive and if my computer fails early in the dive, I can continue the old-school way. Having just bought a Peregrine, I didn’t want to lay out the money for a second computer. Diving with one is not adequate, a point driven home to me when my Aqualung i330R failed on its second day of use. Simpler tech as a backup is a good safety measure. And I like the way it looks (and it fits fine underwater).
Edit: I pay no attention to the NDL table on the strap
View attachment 727672

That's a fine watch but how exactly are you using it as a backup if you don't mind me asking.
Your DC is constantly calculating your bottom time in real time, how would you switch to your dive watch if the DC fails?