Pin point buoyancy

[JonG1]

I am just wondering if anyone has any tips and tricks for on point buoyancy, I still miss the fine adjustments available on OC from lung volume control.

A lot of our overhead dives are in 5-10m which inevitably makes things tougher but I am on an MCCR which is perhaps more forgiving.

I always check setpoint before adding gas to suit/wing in case I need it in the loop, weighting is correct.

Just wondered if anyone had anything to share.

 

[Imla]

Minimum loop volume

 

[jale]

For 5 - 10m range, I would say that pure O2 RB tricks which is to use your loop to control buoyancy is not that bad

 

[tbone1004]

Minloop and just time in the water. I can move around in 2m of water without issue but it takes a lot of time on the unit to feel where you need to be. Wish there was a magic bullet but sadly not

 

[happy-diver]

Wish I could glue my mask to my face

 

[rjack321]

Do you really need to be on CCR in 5m at all?
How much BO are you carrying?
Lastly, what do you use to fine tune your buoyancy? wing, suit or CL?

 

[JonG1]

There is around 1.8km of underground on the shallow side, and we have a range of projects on to document it, re-line, add line etc.

Access is awkward so a 4 bottle SM dive would be circa 5 trips, CCR and 2 BO is 3 trips. Plus it gives flexibility to be at a given point say 550m and "working" for longer than on OC, with the option to go elsewhere on the return. It's also cold at circa 9 degrees.

BO is usually twin 7s ali or twin 12s both in SM. Depending on the dive.

I am currently mainly using suit and wing for buoyancy.

 

[rddvet]

I think it's just time and getting comfortable. Everytime I'm here in Mexico CCR diving, my buoyancy control goes through the roof because there's so many shallow caves or caves with shallow sections mixed with deeper sections. As said, there's no magic trick. I find it's just deciding where to adjust the bubble from. Normally I do loop first (if excess gas present) then wing, then drysuit. Everybody talks about minimum loop volume. I was taught "ideal loop volume". It's basically the same principal, but my instructors felt pushing minimum loop volume sometimes puts people in the mindset that the loop always has to be at minimum. Their belief is that your minimum loop volume shouldn't always be "minimum". As an example, yesterday I dove Taj Maha and was doing a jump on the other side of the room of reflections, which is a room with a big breakdown pile that comes up through 45 feet up to about 4-5 feet. The jump is just over the top of the shallowest depth. Rather than carry a minimum loop volume, I kept a little bit more gas in my loop than ideal, but dumped a ton out of my drysuit and wing. Both were near empty. That allowed me to get to the jump and then make tiny adjustments by exhaling loop volume through my nose or mouth. I didn't have to occupy my hands that were already busy with dumping my wing. IIt also allowed fine adjustments such as you would in OC. Obviously if I vented too much (which happens) II could easily hit one of my mavs or inflator quickly with one hand (or even a knuckle while still workign the jump).

This is probably a very basic idea for most people, but I have found everybody talks about minimum volume and many people are rigid that it should always be at minimum (able to take a good breath wiithout excess gas left behind but not so lilttle it triggers an adv). Sometimes extra loop volume is helpful, especially in very shallow ups and downs.

 

[JonG1]

Min loop can be a bit nebulous in terms of definition I have found, my fake lungs are almost the same as my real lungs, I find getting too tight on volume is very close to triggering the ADV and shallow I often shut off the ADV, so it becomes a bit of a knife edge between comfortable breathing and pulling a vacuum.

I get the point tho and on MCCR it's useful to check your po2 whenever a buoyancy adjustment is required to see if that's what get gas first.

What i miss from oc, is the option to use lung vol to lift you off the line putting a jump in for example.

Rddvet I will see if I can use the lungs more for the pin point stuff tho.

 

[rddvet]

Min loop can be a bit nebulous in terms of definition I have found, my fake lungs are almost the same as my real lungs, I find getting too tight on volume is very close to triggering the ADV and shallow I often shut off the ADV, so it becomes a bit of a knife edge between comfortable breathing and pulling a vacuum.

I get the point tho and on MCCR it's useful to check your po2 whenever a buoyancy adjustment is required to see if that's what get gas first.

What i miss from oc, is the option to use lung vol to lift you off the line putting a jump in for example.

Rddvet I will see if I can use the lungs more for the pin point stuff tho.

I'm on mccr as well. I agree that min loop is a nebulous term, but find too many people take it as having to be at the minimum all the time. I still do find myself breathing in and holding it when I expect I'm going to descend a little. I don't know that that response will ever go away. I also agree the thing I miss most when not on oc is that ability to hold a breath or inihale to get a tiny bit of lift.