Displacement of Scooters at Depth - Spun off from the A&I Discussion about Nothernone

[lv2dive]

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A ScubaBoard Staff Message...

Interesting discussion spun off from Accident & Incident Discussion - Northernone - aka Cameron Donaldson

Thank you!

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You may be aware of this but for those who are unfamiliar with scooters/dpvs.... although dpvs may weigh 40-80 lbs on the surface, in the water they are neutrally buoyant or they would not be usable.

So in order for this theory to hold water, the scooter:
A) would have to have flooded suddenly in the middle of a dive (not impossible, but unlikely)
B) would have to have ingressed enough water weight to become an “anchor” so quickly that Cameron didn’t have time to deploy his cutting devices to cut the leash.

I’ve done support on project dives where SS scooters have been taken to depths past 300 feet so I personally doubt that it flooded due to depth changes when it was working fine for the first part of the dive.

 

[Akimbo]

Perhaps just a silly idea on my part...

The thought was the scooter going significantly negative 40lbs or so due to a flood and getting pulled down to 240ish feet in a rapid descent.

No possibility is silly when considering what-if scenarios because the discussions are enlightening to any number of readers. Cameron would like that.

Taking it to a possible, but less probable extreme, the scooter housing could implode causing a shock wave sufficient to do considerable damage to a limb or render a diver unconscious. Imaginations can run wild with very little hard information, but that process can help prevent an injury in the future. Cameron would like that even more.

 

[ReefHound]

I will not speculate on what MAY have happened - I simply don't have enough data.

However, in looking at probabilities that might contribute to a disaster scenario involving a scooter, I fully agree with Kate on the improbability of 'A'. As for 'B', I am having trouble imagining a scenario where I could not unhook from my scooter. (I do not have any information on how Cameron may have rigged his scooter.) For me, at least, unhooking from my scooters (Oceanic Mako, or Halcyon T16), even when either is operating at full forward thrust, is not particularly difficult, and doesn't require a cutting device - the point of attachment is a bolt snap, on a D-ring on my crotch strap. So, I see 'B" as equally improbable.

What would pull you through the water faster, a scooter at full thrust or a 40 pound weight? I don't know how he had it rigged. He just lost his old scooter a week earlier when it got away so perhaps he changed how he secures it.

 

[Colliam7]

What would pull you through the water faster, a scooter at full thrust or a 40 pound weight? I don't know how he had it rigged. He just lost his old scooter a week earlier when it got away so perhaps he changed how he secures it.

The question is, is there a likely scenario where, even with a 40 lb dead weight, a person - not otherwise incapacitated - could not unclip in a manner timely enough to prevent being pulled to the bottom. And, I do not have any reason to believe that is an event of sufficient probability to warrant serious consideration.

I actually have some experience 'untying' from a significant dead weight (a metal spar, much heavier than any scooter I have ever encountered) underwater while being pulled by current, and all that was required was for me to secure myself to the weight (something as simple as wrapping my legs around it) in such a way that I could create enough slack to unhook. In that case, it was actually more difficult because I was trying to release an anchor hook, not a simple bolt snap. Again, I do not have any information on what may have happened to Cameron, I am simply considering probabilities.

 

[lv2dive]

I agree with @Colliam7 - if there was a scooter that was getting away from me, and I felt the need to detach the scooter from my person bc of weight or thrust, i would first try to unclip the scooter, then go to a cutting device. The reason I spoke to cutting devices instead of unclipping the scooter (as @Colliam7 referenced) was to attempt to pre-emptively address any concerns about inability to unclip bc of thrust.


I have a fairly wide circle of diving acquaintances and to a person, the leashes (rigging) are all of a material that can be cut with a cutting device. I recognize that this is not common knowledge for people who do not use scooters so I apologize for not being more clear in earlier posts.

What would pull you through the water faster, a scooter at full thrust or a 40 pound weight? I don't know how he had it rigged. He just lost his old scooter a week earlier when it got away so perhaps he changed how he secures it.

 

[Diving Dubai]

While I’m also in complete agreement with both @Colliam7 and @lv2dive and have my own experiences with a scooter to compliment their point of view. I’m also reminded of the Tech diver in a deep cave in Europe last year who for whatever reason didn’t/couldn’t disengage his scooter and followed it down past its crush depth (+ 200m) to his death

Not that I’m for one minute suggesting this is the case in this instance but we should remember the lessons of others that it can happen

 

[JohnnyC]

I use a Wichard snap shackle for my scooter leash. Easier than a bolt snap to get away from if you need to.

 

[Storker]

in order for this theory to hold water, the scooter:
A) would have to have flooded suddenly in the middle of a dive (not impossible, but unlikely)
B) would have to have ingressed enough water weight to become an “anchor” so quickly that Cameron didn’t have time to deploy his cutting devices to cut the leash.

That can happen: Diver dead in Font Estramar, France

Not saying it did happen, though. Just providing a data point showing that it's indeed possible.

 

[Dan]

That can happen: Diver dead in Font Estramar, France

Not saying it did happen, though. Just providing a data point showing that it's indeed possible.

Thanks for the link. The scooter imploded at 214m (702'). That's way deeper than 150'.

 

[JohnnyC]

There's a difference between a scooter flooding, and imploding. A significant difference.