1997 Deep Dive/Shark Attack.

[HalcyonDaze]

I guess blaming a shark, especially large and vicious, is a better story than a discussion of the divers hubris.



Bob

That's something we often see in accident discussions on this board, there's a reluctance for some to admit that their friend or loved one was the victim of their own lapse in judgment. I saw a little of that in one case I had a somewhat distant personal connection to; when the investigation report was finally released it showed the deceased had jumped off the boat with his pony bottle reg in his mouth instead of his primary - a very simple, yet fatal mistake. We had another instance on here a while back where a somewhat notorious journalist seemed completely unwilling to admit his friend had pulled the wrong tank out of his garage, refused to analyze it despite warnings from friends, went deep into a cave with a tank that was nearly pure O2, and drowned due to toxing.

The researcher I talked to took his trimix class with a guy who at one point held the record for a deep air dive at 440 ft; apparently that was in the 1980s before trimix was available outside the military and commercial diving. I didn't ask what kind of support equipment was required for such a dive; I would imagine you would need a small truckload of tanks for deco.

 

[electric_diver]

We had another instance on here a while back where a somewhat notorious journalist seemed completely unwilling to admit his friend had pulled the wrong tank out of his garage, refused to analyze it despite warnings from friends, went deep into a cave with a tank that was nearly pure O2, and drowned due to toxing.

That guy was in the denial stage of grief.

 

[ReelHard]

If anyone knows the family personally please PM me. Thanks

 

[InTheDrink]

One thing that doesn’t stack up for me is if they really only achieved 292 ft (88.5m) on presumably a bounce dive I’d be surprised if they were hit by OxTox that quick (obviously I don’t know run times). That’s a PPO2 of slightly more than 2.0. For a prolonged period I can see this being a problem. On a bounce not really. So something happened in or around that depth. Was the SPG recovered, presume so.

I’m not saying the dive wasn’t ill advised but assuming the max depth of 292 they have is accurate I would imagine something other than narcosis or OxTox were at least the only drivers and something happened around that depth. Pure speculation but I’m also betting they’d dived deeper on air before so the shark theory shouldn’t be completely ruled out.

If they had dived deeper then that would be different.

 

[AfterDark]

There is a lot of strangeness in this thread... A giant, prehistoric tiger shark, deadly narcosis, conflicting reports...

It really seems strange that one of the few shark attacks in the entire history of the island just happened to occur on a dive that most experts would call unreasonably dangerous (based on what is known.)

Agreed a 500FSW dive on air SCUBA is dangerous at any time but all of what is known now wasn't known then. The degree of danger was unknown 1997, we've learned a lot since then. Additionally some of what we learned is due to the boldness of divers like these two in the story.

Sharks can be large and are always wild animals, like other wild animals, such as lions, tigers and bears they are unpredictable and maybe like lions, tigers, and bears are also territorial or protective of a source of food. Nobody knows what was at 300FSW, maybe something the shark "owned" was there?

I watched a NATGEO doc recently taken off Hawaii where divers were filming several large tiger sharks feeding on a whale carcass.
The tiger sharks abruptly took off. A few minutes later a very large GW later ID'd as Deep Blue 20ft long appeared out of the depths and began feeding on the carcass. I don't know if that was a clever piece of film editing or if it actually happened that why; if it did happen as appeared it would indicate to me that some degree territorialism was shown and respected by other large predators.

Later other large GWs showed up, it appeared one found the diver's RIB too close to the carcass and bit it 2x's in the same spot!

 

[HalcyonDaze]

Agreed a 500FSW dive on air SCUBA is dangerous at any time but all of what is known now wasn't known then. The degree of danger was unknown 1997, we've learned a lot since then. Additionally some of what we learned is due to the boldness of divers like these two in the story.

Sharks can be large and are always wild animals, like other wild animals, such as lions, tigers and bears they are unpredictable and maybe like lions, tigers, and bears are also territorial or protective of a source of food. Nobody knows what was at 300FSW, maybe something the shark "owned" was there?

I watched a NATGEO doc recently taken off Hawaii where divers were filming several large tiger sharks feeding on a whale carcass.
The tiger sharks abruptly took off. A few minutes later a very large GW later ID'd as Deep Blue 20ft long appeared out of the depths and began feeding on the carcass. I don't know if that was a clever piece of film editing or if it actually happened that why; if it did happen as appeared it would indicate to me that some degree territorialism was shown and respected by other large predators.

Later other large GWs showed up, it appeared one found the diver's RIB too close to the carcass and bit it 2x's in the same spot!

1997 wasn't the dark ages when it came to deep technical diving. The first fatality on scuba in 1947 was a Cousteau associate, Maurice Fargues, who died attempting to set a depth record on Cousteau's Aqualung. His maximum known depth was confirmed by his shaky initials scrawled on a slate at 385 ft on the descent line. By that point nitrogen narcosis at depths below ~100-120 ft was already a documented phenomenon, and there are plenty of accounts of experienced divers getting narced out of their skulls at ~200 ft. I can't remember the source but there's a rather vivid written account from Dr. Eugenie Clark of Mote Marine Laboratory of an acid trip-level bout of narcosis at the bottom of Little Salt Spring. At the time the incident we're discussing happened John Chatterton, Richie Kohler, and others were wrapping up their investigation of the U-869 off New Jersey, several years after they had judged compressed air to be too risky to use at 240 ft.

Trying to go to 400-500 ft on compressed air and open circuit - possibly without continuous surface support according to a comment earlier in this thread - was foolhardy given what was known at the time. Given the comparative odds between a double fatality shark attack and two divers pushing past the known prudent limits of their gas mix and gear, I'm going with the latter - even if it doesn't make for as good of a sea story as a monster shark in the depths.

 

[AfterDark]

1997 wasn't the dark ages when it came to deep technical diving. The first fatality on scuba in 1947 was a Cousteau associate, Maurice Fargues, who died attempting to set a depth record on Cousteau's Aqualung. His maximum known depth was confirmed by his shaky initials scrawled on a slate at 385 ft on the descent line. By that point nitrogen narcosis at depths below ~100-120 ft was already a documented phenomenon, and there are plenty of accounts of experienced divers getting narced out of their skulls at ~200 ft. I can't remember the source but there's a rather vivid written account from Dr. Eugenie Clark of Mote Marine Laboratory of an acid trip-level bout of narcosis at the bottom of Little Salt Spring. At the time the incident we're discussing happened John Chatterton, Richie Kohler, and others were wrapping up their investigation of the U-869 off New Jersey, several years after they had judged compressed air to be too risky to use at 240 ft.

Trying to go to 500 ft on compressed air and open circuit - possibly without continuous surface support according to a comment earlier in this thread - was foolhardy given what was known at the time. Given the comparative odds between a shark attack and two divers pushing past the known prudent limits of their gas mix and gear, I'm going with the latter - even if it doesn't make for as good of a sea story as a monster shark in the depths.

Who said 1997 was the dark ages? I simply posted we know more about the subject now then in 1997 along with the statement that a 500FSW was considered to be dangerous in 1997. We know more now the degree of danger then in 1997. Just look at the research done between then and now. What's your issue anyway?

I watched lot of the events you listed happen as current events and followed the events as best as technology at the time allowed.

You go with what floats your boat. I go with we don't know what we don't know, seems more objective too me.

 

[InTheDrink]

It’s all pretty subjective.

Narcosis would have been there. Was it the issue? We don’t know.

PPO2 could have been ~2.0 if they really we pegged at 292ft. Was it the issue? We don’t know.

Shark attack around 292? Or post mortem? We don’t know.

Buddy has one or many of these issues or others like gas? We don’t know.

I’ll concede to far more experience than me but ruling out a shark attack at 292ft as a big scary monster story isn’t sensible either. And it’s all the more plausible

1. Shark bites on the deceased that surfaced.
2. Planned depth 500ft. Achieved depth: 292ft (assuming this is correct from what I’ve read in the posts)

I would be extremely surprised if these guys hadnt bounced deeper than 292 before thinking about a 500ft record. In fact, I don’t believe it.

If 292ft was their maximum depth I’d say any theory is plausible but
1. OxTox at 2.0 PPO2 on a bounce to 292ft seems unlikely
2. Narcosis at 292ft sounds potentially problematic but as mentioned I’d be surprised if they hadn’t done deep air deeper before.
3. Some issue happening in or around 292ft sounds plausible. Buddy issue. Gas issue. Kit issue. Shark issue.

None are implausible but I’d certainly not rule out a shark attack of a combo of some of the above.

I think one thing we can all agree on however is that it was an extremely ill advised dive, even for a bounce.

I love sharks and dive with them a lot. Generally extremely safe until they’re not.

And being narced at 292 and getting bumped by a tiger might indeed be like a very bad trip.

 

[TooManyHobbies]

This thread has been really interesting. I obviously have no knowledge of the event, but I can jump on the conjecture train for thought experiment purposes. It helps my training and understanding of diving to work through stuff like this, so please help me if I get anything wrong.

Pictures at 292 feet don't mean that was exactly where the dive ended, I'd assume they went past that just based on the probability they didn't photograph their last moments. I'd be curious to know at what increments they were taking pictures.

Narcosis that deep to some extent would be likely, even if just a little bit. So maybe they started to descend faster than they should have, maybe they just stopped taking pictures. Some kind of mistake probably happened or they'd have survived.

So we have narc'd or semi-narc'd divers, burning air very quickly. PPO2 topped 2.0 at about 280 feet and continues to climb. At 500 feet, we're looking at around 3.4 for the PPO2. Maybe you can withstand that for a few moments, but probably not for very long, and they've been well over 1/6 for almost 300 feet of descent, and possibly even some ascent.

Oxtox causes convulsions at its most extreme. Sharks attack people who are flailing a lot more than people who are calm. It's possible that oxtox set in and one of the divers began convulsing, attracting a shark.

Did I miss anything?

 

[InTheDrink]

Conjecture once more but would they have a camera in 1997 that recorded the depth of photos. I don’t know but I’m guessing now. Hence my take is that the max depth was 292ft according the the deceased’s SPG. Please correct me if I’m wrong about this.

If I’m guessing correct and it was intended to be a bounce dive (all likely IMO but still total conjecture) then OxTox and Narcs (@292ft) seem to be unlikely to be the primary cause but could easily be major contributing factors.

Gas, kit, shark and buddy issues seem a lot more likely.

Obviously if they were substantially deeper than 292ft my conjecture would be different.