Deep CCR Diving on the RBJ wreck in Pompano Florida - MOD 270 FSW

[MalibuJerry]

Nice video, thanks. Is there always that much ambient light?

 

[ajtoady]

I can not speak for the guys doing this dive or the OP, just myself and my buddies. We do carry enough bailout and very very very seldom rely upon team bailout.

The deco and bailout gas needed for this dive is very dependent upon both how deep we venture and our bottom times. If we are lazy and do not want to carry 3 tanks then we will limit our bottom time to allow for less bailout, but if we want to deal with the 40 of O2 also we will stay a bit longer.

If I figure a max depth of 250' and a bottom time of 27 minutes, I will end up with about 100 minutes of deco and will need 80cf of 18/45, 80cf of 50%, and 40cf of O2. My total runtime will be almost identical whether I am on CCR or bailed out to CC.

I might be a little off on the exact numbers since I am doing this off the top of my head. This is one of our typical dives that we just use the same plan for each time.

Thanks for the reply! As stated I have no idea and was curious as to the requirements when doing deep on CCR.

 

[ScubaDive4Me]

Nice video. Makes me almost want to get into rebreathers and tech diving. The absolute serenity at that depth with little noise.

 

[wedivebc]

So no body wants to answer the question?

Tony, many tech divers are reluctant to post details of their dives on forums like this for several reasons. One the large peanut gallery population that read on the internet that you should follow such and such a schedule using so and so gas. And those who feel they can actually attempt the same profile that they read on the internet.
Basically on deep dive CCR ascent profiles follow the same shaped curve as OC deco profiles. If you have a problem you may either carry all your own bailout gas or share some of your teams of course that would have to be determined prior to starting the dive. When bailing out you become an OC diver and must follow the OC ascent profile you have arranged in your contingency plan.
Or you can just go down with some random gas and hope for the best and those guys are out there. I choose the former for myself though.

 

[EL Pistoffo]

Pretty good visibility and light at 270 fsw.
The youtube page says that this video was filmed with a go pro Hero 3+ black in the Hero housing.
According to the Go Pro web page, the Hero housing is rated to 40 mts (130 fsw). Too risky to go so far beyond rated limits.

He may have placed his Hero 3+ in the previous, stronger Hero 3 housing which is rated to 197ft (60m). I heard of divers taking them to 400ft depth successfully.

 

[tphelps]

Cool dive and video. That one shark really took an interest in your friend. HaHa. On a side note, and I am not knocking rebreathers but in reallity you really sometimes don't really carrie enough bailout gas to get you out of a serious deco schedule that a rebreather can get you into to...right? So it is a team assisted return to the surface? Charles and I have talked to great lengths about it. Would anyone care to post the deco stops pertaining to this dive. Still, really enjoyed watching the video and I don't dive a rebreather yet but do embrace them.

Cool wreck! Im kinda with Tony on this one, I THOUGHT I saw a diver with only 1 bailout bottle?? He might have had another on the other side but I couldnt tell from the angle.

Im a trimix CCR diver too, took my Prism2 to 270fsw last Wednesday. For that dive (like the dive in the video) we carried 2 deco cylinders. I had a 10/70 mix in an AL80 that would take me to my 20 foot stop and switch to pure oxygen (AL40) for the remainder of the decompression. And actually Tony, this is enough gas for us. Theoretically, all of our decompression will be done on the loop using onboard oxygen. Because we can fly the units manually too, we can raise our PO2 to give us less deco time (because we can run 1.3, 1.4 PO2 the entire ascent). My team dives DIR so we calculate our necessary gas using "rock bottom." It is simple battlefield SCUBA-math to create an entire deco schedule in our head. But in reality if we had to go off the loop...switch the computer to OC mode and follow it. If system electronics failed, you can go to your backup mixed gas computer.

 

[TONY CHANEY]

The simple answer is to switch to your OC bailout tanks and ascend.

I was not trying to start a debate of OC vs CC or even SCC. I was merrly pointing out that it is not always that simple, as I was told. From a long time friend RB diver, "if you carried enough gas to get yourself in and out of every situation that a RB can get you into then you should not be diving a RB because you will have to be carrying the same amount of tanks as you would in OC." That's all. I was not trying to get anyone to post their profiles, gas used, set points, tank sizes, etc.
I feel that the rather blase answer of we just go to bail out lacks a lot of additional info. Ithink better said, "we go to bail out, signal team members if any, end the dive and get to our staged tanks." Just saying...nothing more and nothing less. I still loved the video and was not trying to highjack the thread.

 

[Dsix36]

I was not trying to start a debate of OC vs CC or even SCC. I was merrly pointing out that it is not always that simple, as I was told. From a long time friend RB diver, "if you carried enough gas to get yourself in and out of every situation that a RB can get you into then you should not be diving a RB because you will have to be carrying the same amount of tanks as you would in OC." That's all. I was not trying to get anyone to post their profiles, gas used, set points, tank sizes, etc.
I feel that the rather blase answer of we just go to bail out lacks a lot of additional info. Ithink better said, "we go to bail out, signal team members if any, end the dive and get to our staged tanks." Just saying...nothing more and nothing less. I still loved the video and was not trying to highjack the thread.

Granted your way to answer the question does sound more dignified, but in reality, many times were are diving a very "loose" team and may have different dive missions planned. I might not have time to find my buddies or let them know. We don't stage tanks due to the possibility of getting blown off the wreck and not being able to get to them if needed.

Perhaps I should have posted this instead:

The short answer is to..............., rather than having it appear so blunt.

 

[TONY CHANEY]

Fully understood. Thanks.

 

[Belmont]

"I had a 10/70 mix in an AL80 that would take me to my 20 foot stop and switch to pure oxygen (AL40) for the remainder of the decompression."

tphelps, please confirm the mix that can take you to your 20 foot stop.