Review Fathom Gemini 010

[boriss]

Could some dm me as well? Especially about Ellis, I couldn't find any info on him.

Here's the report for Ellis: https://nsscds.org/wp-content/uploads/2023/01/Devils-Eye-2021.1.21.pdf
- PO2 dropped due to an O2 inline shutoff

Here's the report for Hahn: https://nsscds.org/wp-content/uploads/2023/01/Roaring-River-2022.10.14.pdf
- Use of improper gas for planned depth

Excellent in-depth analysis of the second report here: An HF perspective of the Roaring River Fatality

EDIT:
I've been researching this stuff for an entire day and one more thing I'll add is that I've found a lot of information of what @grantctobin was probably referring to in this thread: Virginian diver dead at 190 feet - Roaring River State Park, Missouri

There are video's, links to posts, articles, etc. A very interesting read, despite the early conjecturing, some misinformation, misunderstanding, and so on. I certainly learned a lot as part of this proces and it made me really think about some of the choices I'm making as a new CCR diver. For example, I was considering going with independent BM doubles for multiple gasses (see vid below) for my Choptima setup and am definitely not going that route now. There's really no need for it and it just creates a potential to make mistakes. So fully manifolded doubles for me and if I need additional gasses I'm going to suck it up and side-mount them like I did with OC.

 

[Underwater Tourist]

"The victim did not have a HUD or alarm system on his CCR"
Unfortunate that such things continue contributing to dive accidents

As a temporarily thread hijack, what makes people forgo a secondary monitor? Is there some tradeoff I am not aware of?

 

[TheScubaPanda]

"The victim did not have a HUD or alarm system on his CCR"
Unfortunate that such things continue contributing to dive accidents

As a temporarily thread hijack, what makes people forgo a secondary monitor? Is there some tradeoff I am not aware of?

I guess you could say "a flashy thing in your face could be annoying". Maybe you could argue it's another thing that can break.

Not saying I agree with any of these. Just stating what I heard around.

To be fair, a HUD is fairly simple to ignore and if you don't want to look at it, it won't magically make you know there is a problem. Now the reality is that if I see any red flash during my deco I'll definitely look really my handset. And if I see the alarm mode at any time (flashing like crazy) it would catch your attention real fast.

 

[flymolo]

I think it’s mainly due to cost and probably a degree of complacency. I’ve also heard the argument that if you can forget to check one monitor you can forget to check two monitors? I don’t really buy that argument personally.

 

[TheScubaPanda]

I think it’s mainly due to cost and probably a degree of complacency. I’ve also heard the argument that if you can forget to check one monitor you can forget to check two monitors? I don’t really buy that argument personally.

To be fair unless that HUD is flashing like a christmas tree it's very easy to ignore ... Which in a sense, it's sort of its primary job. Giving you redundancy of display in case of problem with the primary handset and alert modes to catch your attention. Anything else, to me, is icing on the cake

 

[flymolo]

To be fair unless that HUD is flashing like a christmas tree it's very easy to ignore ... Which in a sense, it's sort of its primary job. Giving you redundancy of display in case of problem with the primary handset and alert modes to catch your attention. Anything else, to me, is icing on the cake

I sort of find the opposite. I don’t pay deliberate attention to it, but the minute it changes my brain notices.

 

[tbone1004]

"The victim did not have a HUD or alarm system on his CCR"
Unfortunate that such things continue contributing to dive accidents

As a temporarily thread hijack, what makes people forgo a secondary monitor? Is there some tradeoff I am not aware of?

I would recommend reading the threads about that incident as there are several very long threads about redundant ppO2 monitoring that came up as a result.

 

[rjack321]

Another Inline o2 shutoff issue. Some instructors are still promoting their use. One went as far as making a video to show its impossible to go hypoxic even with it shut off.

AG did a very similar video back when UTD released their "all manual" CCR. He was pilloried for it on TDS and burgerworld (RBW). Social media has reached peak BS nowadays and this second iteration had barely a peep.

It's totally false that a shut off O2 feed can't lead to hypoxia. It can be a challenge to go hypoxic at the surface if your starting ppO2 is higher than 20.9% ambient - because if your ppO2 is (eg) 0.8 at the surface you will run out of loop volume before you can breathe that down to hypoxic. But basically anywhere else it's very possible to go hypoxic on a CCR with no O2 flowing.

 

[sea_ledford]

As a temporarily thread hijack, what makes people forgo a secondary monitor? Is there some tradeoff I am not aware of?

My hud flooded last time I dove with my unit due to a cracked housing, worked fine through the dive. I didn't figure it out until I really broke down the unit, including pulling the battery out of the hud. (Hud is an AV1, the battery is in the hud itself, connects directly to a fischer cable. Super slick... aside from the flooding part). Anyway, the manufacturer is in Russia and at the time I couldn't get anything from Russia, still not sure if I could at this point. If an exciting opportunity came up to dive my CCR with short notice, I would certainly be tempted to run it without a hud. Would I actually do it? Probably not, I haven't dove it since then, but with a big/rare enough opportunity? Man, it would be tempting!

If I had the lead time I'd order something else, but the complacency is certainly tapping me on the shoulder.

 

[lostsheep]

Probably a dumb question but where does the DIL MAV feed gas into the loop? Looking at Fathom's page on the Gemini it is not obvious to me. I see 1 port on the head but out of ignorance would think that is for O2. Does the block holding the manual add buttons feed both dil and O2 through the same hose?