Diving air to 60m

[rsingler]

But my rate of breathing does change depending on what I’m doing. What I thought Simon Mitchell was saying is that some people don’t respond to CO2 build up and their rate of breathing stays the same hence CO2 starts to build. Have I missed something?

Nope! You've got it right. In that case, no headache means that thus far, you've likely not developed significant hypercarbia due to the conservatism of your dive profile. It doesn't mean that your risk is lower, given the innate risk of high density gas compared with helium. But you've stayed out of trouble. That's good. If you can guarantee dives with no extra effort, you can continue as you have been. From a cost standpoint, you clearly win. But I hope you would concur that your contingency margin is rather less than with Trimix. And then there's the "night vs. day" difference that the Ginnie divers have pointed out regarding more subtle perceptions when they switched from air to trimix inside the cave.
But yes. It's sounds like you have a standard response to CO2. Thanks for replying!

 

[Celt]

I cannot speak for @Dr Simon Mitchell, but from a few exchanges I had with him (I am quite interested in O2 retention) I understood that being CO2 tolerant only moves further up the concentration at which you have a response to it.
So the only thing that happens is you can walk closer to the precipice whitout feeling it but it is still there.
So this is also what @rsingler was saying: you (or any tolerant person) might be closer to the edge that you (he) know(s).
Be careful ... a deep CO2 hit is a non recoverable loss of control on respiratory rate unless you have a huge volume of gas ... and based you the discussion your reserves appear to be thin.

Cheers

I don’t understand what you mean by tolerance to CO2 but I have a very simple rule, If I can’t take a nice long slow and easy breath I stop what I’m doing until I can. And if for any reason I don’t quite feel right I end the dive no matter what depth I’m at, I never ignore what my body is telling me.

 

[Wingy]

Have you been to anywhere else where AIR is the only option? I have been to a few and as far as I know it is still the only breathing mix available in those places.

Hell yes, private LOB in PNG to Solomons (Uepi) Rangiroa with a French CMAS op a decade ago, never bothered asking since -
Bangka the first time I went there - full disclosure it never came up as to what I wanted to dive but I didn't see any Nitrox tanks - Cubadak in Sumatra did not offer Nitrox may do now - Tanna in Vanuatu 2 years ago, Madagascar which I'd say would be seasonal as we were there in cyclone season and had to dive with the last chance texaco operator first time out and the cetacean guy who opened up his friends dive shop due to demand second time. I'm pretty sure there was no Nitrox but I think from memory she dove on air too. In Reunion I believe there was a tank mixup and I dove Nitrox. Hard when you don't speak French or Malagasy.

Gas blending may be available in Madagascar during the diving season - roughly on topic Vanuatu has a full range of gases including He and different configurations/rebreather to side mount at Santo - totally off topic @Centrals did you hear Sky at South Sea Divers in Sabang passed away today?

 

[dmaziuk]

I don’t understand what you mean by tolerance to CO2 but I have a very simple rule, If I can’t take a nice long slow and easy breath I stop what I’m doing until I can. And if for any reason I don’t quite feel right I end the dive no matter what depth I’m at, I never ignore what my body is telling me.

Side note: "CO2 tolerance" as understood in endurance training is basically that: learn to keep your breathing slow and easy during intense physical activity.

 

[Dan]

Cubadak in Sumatra

How's the diving there?

 

[Centrals]

totally off topic @Centrals did you hear Sky at South Sea Divers in Sabang passed away today?

No I did not.
I believe he was suffering from cancer.
Another old timer has gone as he had been in Sabang for so so many yrs.
RIP.

 

[Wingy]

How's the diving there?

It's Indo, but not as we know it.

As its south of Padang its Indian Ocean diving not coral triangle caliber.

I was surprised by the amount of quite big grouper and wrasse family - lots of octo's and a massive sponge garden so viz Iz not the best. Had one of the most interesting dives of my life there - head inside a barrel sponge looking at an octopus and a cuttlefish sharing the space when an 8.6 earthquake hit lol - felt nothing. There is a tiny island just next to cubadak they use for night dives - that was the exception and a very very good night dive spot.

Ive heard the island has become quite busy on weekends but it's a groovy little middle of nowhere place to chill. I wouldn't return as a designated dive trip.

 

[mafi]

If I can’t take a nice long slow and easy breath I stop what I’m doing until I can.

THIS! This is something I miss looking at so many divers (luckily mostly OWDs I lead, not tech divers). They just say 'I was breathing really hard on this dive' but do not take 30 seconds to calm down /rest/fix buoyancy or trim issue that is causing them to breathe so hard.

I do not understand that. I absolutely love the feeling of breathing reeeeeeally slow and thinking OMG I am barely using any gas, I can be here forever!

 

[Fibonacci]

The book is still available second hand ex Australia, but at a rather hefty price.
Just look it up on ABEbooks, or Bookfinder, etc. I don't think the Kindle version would do it justice, but better that than nothing.
I highly recommend this book - The Last New Guinea Salvage Pirate - to anyone with an interest in history!!!!!

Been reading this book over the last few days... a cracking tale of diving in PNG back in the early days.
Really fascinating if you've ever been to Rabaul and some of the key Japanese centres of WWII in PNG.
Welcome to Salvage Pirate
Entertaining review by Bob Halstead attached

 

[Khrissi]

Am stealing that Kipling quote off you Fibbonacci ! K