Feedback on recent two-tank and dive limits

[34109411]

Appreciate it

i ve just got my sherwater also i ve got 7
dive on it. I will use it for sidemount i bought two transmitter. I will let you know how it goes either way the two tank monitoring.

Be safe

 

[oldschool45]

lizzzzz being the "fairy godmother/father" to a new diver can be very distracting. I've had a few dives with my new diver wife where I was comfortable covering me own safety but watching her back too was more than a little taxing for me. Her OW dives (in the Keys) were easy and her follow-up dives were cool. But some of the drift and deep dives for her AOW had me questioning my ability and my sanity. As she has matured as a diver it has gotten a lot easier. I can't tip/bribe/thank her excellent instructors enough. Now I have a dive buddy that is very competent. She now has to get more comfortable as your son will be. She dives a Peregrine and I dive a Garmin Decent. With both set to high conservation they track pretty well. I've pretty much relegated the old RDP (Recreational Dive Planner) card to museum status. Enjoy the diving!

 

[old frogman]

For technical diving I definitely see the value of the GF. This is assuming that the respective technical diver understands the GF concept and its intended application (I suspect some do not and just follow the fashion/crowd).

However, I question the validity of GF for recreational diving. I strongly suspect that 99.9% of recreational divers who use dive computer with GF have no idea of the implications of their use.

A better and simpler alternative for the recreational divers is a dive computer with simpler and easily understandable microbubble conservative levels, for example, level 0 to level 5.

Warm Water and moderate depth:
L0 - GF 100/100
L1 - GF 90/90

Repetitive dives and moderate depth:
L2 - GF 85/85
L3 - GF 80/80

Cold water, deep dives and high exertion:
L4 - GF 75/75
L5 - GF 70/70

GF lower than 70/70 is generally a waste of time for recreational diving. Stops deeper than 30 feet (9 metres) for recreational diving (which includes decompression for European and UK divers) generally does not produce better decompression outcomes.

 

[KenE]

After close review it appears that both of your ascents were significantly faster than descent and the opposite is optimal. Your safety stop will be longer if you ascend too fast. If a guide says they are extra safe, it is because they want you to trust them, then they aren't and rush. Always watch computer, SI and ascent are critical to your safety.

 

[Belzelbub]

For technical diving I definitely see the value of the GF. This is assuming that the respective technical diver understands the GF concept and its intended application (I suspect some do not and just follow the fashion/crowd).

However, I question the validity of GF for recreational diving. I strongly suspect that 99.9% of recreational divers who use dive computer with GF have no idea of the implications of their use.

That may be the case, but it is really not all that different from recreational computers that give you a choice of setting different levels of conservatism.

A better and simpler alternative for the recreational divers is a dive computer with simpler and easily understandable microbubble conservative levels, for example, level 0 to level 5.

For the diver that doesn't need to go into the custom GFs, the Shearwaters, and most other DCs running Buhlmann offer simple conservatism factors. In the case of the Shearwaters and Garmin's (those are the two that I'm most familiar with) there are 3 options. Low, Med, and High conservatism. How is that harder than the L0 to L5.

High = 35/75
Med = 40/85
Low = 45/95

From there, the diver has the option to use a custom setting. If they want. However, for the diver that doesn't really understand the GFs, it's best to use one of the presets. Custom GFs are just an option. No one is required to use them.

 

[Mobulai]

Why is even GFLo relevant for any NDL diving; isn’t the GFHi the only factor that makes a difference here?

 

[inquis]

Why is even GFLo relevant for any NDL diving; isn’t the GFHi the only factor that makes a difference here?

Exactly, right. If you're under GFHigh, you can surface (by definition). Shearwater and Garmin, for example, ignore GFLow for NDL dives. I suspect most others do as well, but it's easy to check if custom GFs are supported.

 

[Blackcrusader]

This feels like the answer ^^^

I’m not familiar with how gradient factors work and am sure I would have been less concerned if I was. Not sure if it’s me not remembering from my dive training, that OW and AOW courses didn’t go into it in detail, or both. Either way, it’s on me to learn now. Thanks for this

The issue is you have a dive computer and that you do not understand the settings or functions.
Gradient Factors are not taught in OW or AOW classes. There are threads here on gradient factors.
Also you should upload your dive logs and study them so you learn from them. So yes after I bought my Pedix in 2018 I downloaded and read the user manual many times, updated my firmware and then spent many an hour learning what my Shearwater functions are. I've done over 1000 dives on it now and I look at my dive logs from time to time. Great piece of kit but you need to understand it.

Plenty of threads on this forum on how Gradient Factors and Shearwater settings work posted. I had a woman telling her guide I must have been going into deco as she did not even know her own Shearwater settings. Not only that her Shearwater was set on fresh water and she was salt water diving. I asked her if she knew what settings she was using and she had no clue. Just strapped it on and never looked at the settings.

It really is imperative you learn about your DC.

Also a guide should never be your decision maker for a dive you have to be independent of the guide.I often dive with guides who use Suunto devices and they have far less NDL on repetative dives than I do.
So they need to ascend to avoid deco as I can stay deeper for longer with plenty of NDL.

Even if you show NDL of 1 minute you are not in deco. Even at zero you are not in deco. Also learn about the adaptive stop and also your last stop depth settings. I set my last stop at 3m.

 

[Blackcrusader]

However, I question the validity of GF for recreational diving. I strongly suspect that 99.9% of recreational divers who use dive computer with GF have no idea of the implications of their use.

I'm a recreational diver and I bought my Perdix knowing that it has a wealth of information for me on dives. Also bought it due to the great digital display. I also dive in OC Tec mode and have setup my Perdix for how I want the display. I have buddies who also use shearwaters and we all dive on the same GF settings.

Sometimes we also do short 10 or 15 minute or so Deco added time and often clear deco obligation during the dive. We can clear deco and continue on with the multilevel dive. The fact that so many divers have a DC that they have no clue about is the sad thing. I've had divers with their alarms beeping pointing at me. They think my Perdix is going off. After the dive I have to tell them my Perdix doesnt have audio alarms and that is their own DC beeping.

 

[Blackcrusader]

Why is even GFLo relevant for any NDL diving; isn’t the GFHi the only factor that makes a difference here?

It's relevant when people exceed NDL as some do unknowingly. They dive and see something interesting and never check their depth or NDL.