Two missing on submerged Great Wall - China

[Johnoly]

It's now speculated electrofishing by local fishermen caused this fatal accident.

I'll be the first to call "bullshet" on electrofishing.

Electrofishing is usually done in very shallow depths less than 12 feet (so the surface fishers would see the divers below actually). 2nd for electrofishing to be effective you must maintain a fairly stable distance between the 2 electrodes. This is usually done with fiberglass poles but I have seen it done with wood also. Electrofishing isn't killing the fish, it's "stunning' the fish to be scooped up in a net before they recover. It is usually done with a generator on a boat but you can use car batteries which don't last long at all depending on the amps applied. You can make the batteries last longer by pulsing the amps instead of continous current. To terminate 2 humans in wetsuits at normal dive depths would be next to impossible. Again, it doesn't kill, it just stuns the fish.

The main use of electrofishing here in the US is for invasive fish like asian carp or other non native species.

 

[claymud]

I'll be the first to call "bullshet" on electrofishing.

Electrofishing is usually done in very shallow depths less than 12 feet (so the surface fishers would see the divers below actually). 2nd for electrofishing to be effective you must maintain a fairly stable distance between the 2 electrodes. This is usually done with fiberglass poles but I have seen it done with wood also. Electrofishing isn't killing the fish, it's "stunning' the fish to be scooped up in a net before they recover. It is usually done with a generator on a boat but you can use car batteries which don't last long at all depending on the amps applied. You can make the batteries last longer by pulsing the amps instead of continous current. To terminate 2 humans in wetsuits at normal dive depths would be next to impossible. Again, it doesn't kill, it just stuns the fish.

The main use of electrofishing here in the US is for invasive fish like asian carp or other non native species.

According to an interview report by local news, the SMB was witnessed by a diver for a while before it disappeared, which suggests two victims were ready to reach the surface when they suffered an accident. So the possibility remains that the fishermen failed to notice the divers even they were able to see them. Second, I didn't say the electrofishing directly killed them. It was more like they were drowned after losing consciousness.

Still, they are speculations. Let's wait for the official report. Personally, I hope this electrofishing story is not true because otherwise it would be too pathetic for these two excellent divers.

 

[Dan]

I'll be the first to call "bullshet" on electrofishing.

Electrofishing is usually done in very shallow depths less than 12 feet (so the surface fishers would see the divers below actually). 2nd for electrofishing to be effective you must maintain a fairly stable distance between the 2 electrodes. This is usually done with fiberglass poles but I have seen it done with wood also. Electrofishing isn't killing the fish, it's "stunning' the fish to be scooped up in a net before they recover. It is usually done with a generator on a boat but you can use car batteries which don't last long at all depending on the amps applied. You can make the batteries last longer by pulsing the amps instead of continous current. To terminate 2 humans in wetsuits at normal dive depths would be next to impossible. Again, it doesn't kill, it just stuns the fish.

The main use of electrofishing here in the US is for invasive fish like asian carp or other non native species.

This makes a lot of sense to me because I have seen electro fishing before back in Indonesia. They do it in a shallow river (may be up to below the knees). They do it in pairs. One fisherman have 2 long bamboo poles with a + cable strapped on one & - cable strapped on the other pole wearing rubber boots, just wading on the river zapping downstream areas under rocks with the poles 1m apart to stun critters / fish hiding under rocks, mostly shrimps, while another fisherman about 4-5m downstream with a fishing net ready to catch those stunned shrimps before they regain consciousness & swim away.

 

[kelvkwok]

How many surface support team members during the 4 divers in 2 teams underwater?
Assuming a fisherman took Xu's SMB while she was about to surface or signal to the surface by attaching a hand written slate, it should be a surface support team member to spot that, and pick that rather than a pass by fisherman, right?
Just curious.

 

[alewar]

It seems the bodies have been recovered:

Two divers recovered after drowning at the Great Wall - People's Daily Online

 

[LiteHedded]

it's never the divers or the rebreather. but electrified fishing is a new one...
i was thinking this would be a double heart attack for sure

 

[alewar]

some more details: Bodies of 2 expert divers are found - USA - Chinadaily.com.cn

 

[LiteHedded]

Did both of these divers have a GUE rebreather certification? We're they diving the standard GUE configuration?

Article says at least one diver was borrowing a unit but it's my understanding they teach the course (or have in the past) even if you don't own one

 

[FuAn]

Ok,

I knew Denovo or Haijan or Tofu as she was mostly known in the diving community very well. I also knew Sun Hao, as I had been living 6 years in Shanghai before I moved to Houston, TX.

Both were neither officials of GUE nor instructors.
Both were GUE certified.
Xu was the first women in China to get certified Cave 2 not the first Chinese.
Xu did do several translations for GUE, i.e. for Jarrod, at Chinese dive shows and was close to Unscuba / Hui Jin, the resident GUE instructor / GUE organization
The Great Wall project was a Project Baseline initiative conducted by divers around Hui Jin, Denovo Xu, Sun Hao and others, to my best knowledge this was not an "official" GUE Exploration Project.
Xu owned and was certified (IANTD) on a rEvo since 2014 this article vaguely suggests she borrowed a rebreather from someone not wanting to be named which is very suspicious to me.
Sun Hao owned and was certified on a JJ.
Sun Hao was diving his JJ standard configuration not the GUE configuration.
Both to the best of my knowledge were very unlikely to be certified on rebreathers by GUE.
Xu had been diving since "only" 2009 but since went through recreational, all GUE training up to Cave 2, IANTD CCR... as much as I really liked them and is not supposed to be finger pointing, but this fits my general observation that in China divers undergo usually zero to hero training with mostly course diving and very little actual experience undergone.

Having seen Electrofishing conducted for counting invasive species I'd also say would be very unlikely, however it is common practice by Chinese officials that any fatal accident will be blamed on some sort of illegal / unlawful action. If they won't be able to put it on illegal fishing practice, Government will likely call the the diving at this part of the lake, the Project Baseline activities or GUE illegal / unlawful.

Cheers

Christian

 

[LiteHedded]

Thanks Christian. that's helpful