Scuba with RB buddy.

[Duncan Price]

When I dive with RB always look for the route that will allow for the least up/down profile. OC divers should be aware that RBs use more diluent when the profile is a little bumpy so you should try to adhere to a more square dive profile if posssible.

I would echo this remark. When I've been diving with someone on OC I brief them that my ascents and decents will be slower and that I prefer to swim around objects rather than over them.

Duncan

 

[Rick Inman]

From the British SCUBA Association documents. Translate meters to feet and there you have it. Dive Briefing for OC and RB mix.


Dive Briefing
When diving with an open circuit diver a SCR diver should include some rebreather specific
topics to the dive briefing.
- Hyperoxia. Hypoxia. Hypercapnia. SCR diver to inform the buddy of the possible
problems that might occur and present the rescue actions. Brief description of the
signs a buddy should look for to indicate these conditions.
- Controlled Buoyant Lift. A brief statement that this is the appropriate action for all
cases when the rebreather diver is unable to cope with the problem. It should be stated
that in the case of Hyperoxia the rescuer should wait until the casualty is in the
relaxed stage before attempting a CBL.
- Mouthpiece. Mouthpiece must be closed whenever it is not in the mouth.
- Bubble Check. The buddy should be informed of the need for a bubble check within
the first 6m.

Buddy Checks
In addition to standard open circuit buddy checks, you should include the specific items
relating to your rebreather. Of particular importance are:
- Mouthpiece operation. Your buddy must be familiar with the operation of the
mouthpiece in case he/she needs to operate it at the surface in an emergency to
preserve buoyancy from the counter lung.
- Over pressure valve operations. In the early dives, it may be necessary to adjust the
over pressure valve to vary the loop volume. Should the buddy’s help be required to
make these adjustments then he/she should be informed of the valve operations and of
the signals to be used.

Well, we made the dive last night and all was well. My buddy briefed me almost exactly like the statements above. I let him lead, and he sure didn't dive a square profile! Much more bouncy than I like to be, but we kept it shallow (above 80') 'cause he was on 40%. Dive time was about 55 mins, water temp avg. 52F, 15' vis. Lots of big bass that he kept trying to swim up to, thinking that with the RB they wouldn't spook, but they did. Gee, do you think it could have been the 18w HID in their eyes??

As you said, Mech, it was an SCR.

What I did NOT like was that his alt air was one of those Air II, on the inflater deals. If I'd needed air, I would have had to breath off his inflater, and control his and my BC on accent. This is not good, and I told him so. My suggestion was to go H valve and bring along an octo.
Opinions?

 

[Diver Mike]

Hi Rick

My suggestion is now and always to carry a "pony bottle". When I dove my Dolphin, I had it attached to the side of the case with the OxyCheck slide and button mounts, worked great and I had a "real" regulator with a longer hose for my buddy to breath off of. I also was able to mount my dry suit Argon bottle on the other side and I was balanced etc.

Now that I am on CCR, i follow the same practice.

I do not subscribe to the practice of using your SCR gas supply for your bailout supply. I beleive that you need redundant gas supply. It should also be noted during dive planning what the bail out gas for OC bailout needs to be for the depth and length etc of the planned dive. Then plan the dive, dive the plan and that's all there is to it.

Once your buddy gets more comfortable with the control of his SCR his profile will flatten out and he will get twice the gas "milage" out his tank.

Mike...

 

[caveseeker7]

Inflator-integrated 2nd stages are not supposed to be used by the other diver for gas sharing. The diver who has them mounted to their BC is supposed to use them and pass on the primary 2nd stage to the buddy.

That of course doesn't work well on a rebreather.
While the diver is covered, the buddy is not.

Which SCR does your buddy use?
The Dolphin (Camreone's avatar, either black or white),
or the Azimuth (big & black, with 2 clear coated tanks)?

Azimuth have a normal nitrox 2nd stage for bailout, and due to the 2nd 4ltr. tank a pretty good gas supply. If one has been modified with an AirII reverting it to stock is not a problem.

Drägers come equiped with Buddy AutoAir 2nd stage/inflators.
The Dolphin has an IP that is too high for normal 2nd stages and therefor requires a 2 or 3ltr pony tank and separate 1st stage. Adding another 2nd stage to that for the buddy is no problem.
Adding any second stage (including the AirII or AutoAir) to the main tank requires a special H-valve (or adapter) that will take both the proprietary Dräger 1st stage and DIN/yoke 1st of the second regulator.
That leaves the issue of bailout gas, the stock 4ltr. isn't much for two divers, especially late in the dive. not that a two liter tank is sufficient in case you both need to bail.

Either your buddy can add another bailout tank and reg, or even safer you could add a redudant gas supply to your gear. If you get a pony bottle and regulator you will be self-sufficient no matter who you dive with. If either of you sling- or sidemount a redundant gas supply rather than backmount it, it can be passed on to the buddy if needed.

 

[Rick Inman]

Inflator-integrated 2nd stages are not supposed to be used by the other diver for gas sharing. The diver who has them mounted to their BC is supposed to use them and pass on the primary 2nd stage to the buddy.

That of course doesn't work well on a rebreather.
While the diver is covered, the buddy is not.

Which SCR does your buddy use?
The Dolphin (Camreone's avatar, either black or white),
or the Azimuth (big & black, with 2 clear coated tanks)?

Azimuth have a normal nitrox 2nd stage for bailout, and due to the 2nd 4ltr. tank a pretty good gas supply. If one has been modified with an AirII reverting it to stock is not a problem.

Drägers come equiped with Buddy AutoAir 2nd stage/inflators.
The Dolphin has an IP that is too high for normal 2nd stages and therefor requires a 2 or 3ltr pony tank and separate 1st stage. Adding another 2nd stage to that for the buddy is no problem.
Adding any second stage (including the AirII or AutoAir) to the main tank requires a special H-valve (or adapter) that will take both the proprietary Dräger 1st stage and DIN/yoke 1st of the second regulator.
That leaves the issue of bailout gas, the stock 4ltr. isn't much for two divers, especially late in the dive. not that a two liter tank is sufficient in case you both need to bail.

Either your buddy can add another bailout tank and reg, or even safer you could add a redudant gas supply to your gear. If you get a pony bottle and regulator you will be self-sufficient no matter who you dive with. If either of you sling- or sidemount a redundant gas supply rather than backmount it, it can be passed on to the buddy if needed.

Well, don't know the brand of RB. Yeah, he had a pony, which he used for BC inflation/Air II. 19CF, which means knowing how much air would be remaining at all times based on BC use, etc, so there would always be enough gas left for me including safety stop. So during the dive, I kept checking his pony SPG, cause it was MY backup air! There is nothing good in this set up, even with an H valve & octo on the pony. You're right, the best thing is for me to carry my own pony when I dive with him. I don't know, the whole thing seems like a set-up for trouble. I am basically solo diving with a guy on a system I'm not trained on. Are either of us really able to count on the other? I'm starting to think Shaka was right. :11:

I don't know why your buddy doesn't use a normal setup when he's diving with you???

 

[caveseeker7]

As I said, the setup he uses makes him self-sufficient, but leaves you out in the cold ... it's not the way to go.
If he mostly dives with OC equiped buddies ask him to add a 2nd pony with a normal regular on the opposite side. He of all people ought to understand that his setup doesn't provide bailout for you.

However, the best dive buddy is self-sufficient if you really think about it.
If your training skills and equipment make you self-sufficient you won't have to rely on your buddy to survive an emergency and will be better prepared if he has one.
For a good lecture read Robert von Maier's Solo Diving.
Even if you're always buddy up there is a lot of good info.

Last but not least, if you really feel uncomfortable with a (new) RB diver, don't dive with him.

 

[Rick Inman]

However, the best dive buddy is self-sufficient if you really think about it.
If your training skills and equipment make you self-sufficient you won't have to rely on your buddy to survive an emergency and will be better prepared if he has one.
For a good lecture read Robert von Maier's Solo Diving.
Even if you're always buddy up there is a lot of good info.

Yeah, I believe in self-sufficiency and have the Maier book, and I solo dive sometimes. OTOH, I like what I read and see in DIR divers and their team approach.
I'm SOOOOO conflicted! :yl2jump:

 

[wedivebc]

Yeah, I believe in self-sufficiency and have the Maier book, and I solo dive sometimes. OTOH, I like what I read and see in DIR divers and their team approach.
I'm SOOOOO conflicted! :yl2jump:

Perhaps your best bet is to carry your own bailout pony bottle and dive like you do when solo.

 

[Rick Inman]

Perhaps your best bet is to carry your own bailout pony bottle and dive like you do when solo.

Yup. Will do.