Surface blackouts and the freediver recovery vest

[HooSlayer]

Is your lung volume expelled during a surface blackout after a dive? The FRV has this feature where if you sink past ten feet right after surfacing from a dive, it will assume you have blacked out on the surface and inflate.

But since you are weighted to be bouyant at the surface with a lungfull, you wouldn't sink unless you exhaled and the FRV wouldn't activate.

Can someone explain this to me, do you always exhale when you black out and sink?

 

[cdavis]

Normally, larngospasm keeps the diver from exhaling during a BO, until enough time has passed to force an inhale. Better not be underwater when that happens. What can happen is a diver hits the surface, exhales and BOs before he can inhale. Too much weight and he sinks. Thats what the FRV is primed for. The FRV should get the diver back to the surface before the final inhale.

 

[HooSlayer]

thanks! I actually ordered one yesterday but i was curious about this feature. I did suffer a black out 15 years ago and remember researching all of this in depth afterwards but needed some clarification on this

The vest has the option where you have to press a button after every surfacing to let it know you didn't black out, or one where it it just assumes you blacked out if you descend right after surfacing. I think i would forgot to press the button too much with the first option so I will probably use the 2nd variation of the settings.

 

[Bill McIntyre]

The option that requires you to push the button to let it know you didn't black out is obviously safer, but I'm also afraid I'd forget. In particular I'd forget after shooting a fish and hitting the surface pulling on the reel line or float line to keep the fish from tying up deep in the kelp. There is no way I'd remember to then, so I don't enable that.

 

[cdavis]

I'm the same as Bill.

 

[HooSlayer]

The option that requires you to push the button to let it know you didn't black out is obviously safer, but I'm also afraid I'd forget. In particular I'd forget after shooting a fish and hitting the surface pulling on the reel line or float line to keep the fish from tying up deep in the kelp. There is no way I'd remember to then, so I don't enable that.

it would be nice if it beeped like 5 seconds after you hit the surface to remind you....even better or vibrate since i wouldn't want something beeping while spearfishing

in the future when this technology gets even more advanced and integrated with biosensors, it will probably just have a sensor which can tell if you are breathing or not at the surface.

 

[HooSlayer]

I have a follow up question. Lets say you black out at/near the surface without exhaling and are floating face down. After laryngospasm, when it releases, you inhale a bunch of water and start sinking. Vest goes off and you surface again.

Does that fact that you have already been through spasm mean that you will not "wake up" again and would require cpr to be saved at that point?

I'm guessing this is where a difference in safety exists between the setting of pressing the button at each surface interval vs. only having it inflate if you sink shortly after a dive.

 

[cdavis]

With a lungfull of water, the diver is pretty much dead. This is one of those situations when having a snorkel in you mouth might be a good thing.

 

[Bill McIntyre]

With a lungfull of water, the diver is pretty much dead. This is one of those situations when having a snorkel in you mouth might be a good thing.

Back when Terry Maas used to actually engage in discussions on forums like Spearboard before they got so nasty, he actually advocated leaving the snorkel during a dive. I'm afraid I can't recall his rationale though. But as you said, if you inhale water and then sink, you're done for. The vest would inflate and position you on your back on the surface, so at least your body would be easy to recover, and that is no small thing.

 

[HooSlayer]

Thanks, another question. So lets say you have the feature where it auto inflates if you don't press the button upon each surfacing. You experience a black out on the surface and end up face down on the surface floating. Upon inflation, will the vest always turn you onto your back from being face down?

as a side note it would be good to have an alarm that beeps to remind you to press the button everytime you surface, does it do that?

 

[Bill McIntyre]

If it inflates it’s almost impossible to turn face down. When I went on Terry’s boat to try out the first version before it went to market I did manage to roll over but it took a lot of effort and he was surprised that I managed to do it. Since then when I’ve tested subsequent versions to make sure they work I’ve pulled on a toggle to let gas out when I wanted to roll over to swim back to the boat face down. Without a lot of effort you’re going to be on your back with your snorkel out of the water even if it’s in your mouth.

It doesn’t beep.

I get the impression that you are looking for reasons not to buy it unless it’s perfect. It’s not perfect and it didn’t keep me from getting prostate cancer. I’m getting symptoms that I may need a hip replacement but WTF, I’m 80. Only you can decide if it’s worth the money. I don’t expect it to give me life eternal but it might give me life longer and I’ve spent more on a speargun.

 

[HooSlayer]

^ Oh I already bought and received it last week bill. Believe me I'm convinced that its better than not having one. I'm just trying to consider situations where it would fail and what I can do to avoid them.

Just to be clear, I'm not talking about turning face down after its inflated. I'm asking about if you are already face down floating on the surface, and it inflates, will it then turn you over onto your back? It sounds like it will indeed turn you over from what you are saying but I just want to make sure.

sorry to hear about prostate cancer and hip. I hope you can beat it, not have much pain, and continue diving.

 

[Bill McIntyre]

Sorry, I forgot that you had said you ordered one.

I feel certain that if if you are already face down on the surface it will turn you on your back but the best thing to do is try it it yourself. The CO2 cartridges are expensive but you could use a smaller and cheaper one for that test. It would fully inflate on the surface even if it wouldn't fully inflate at depth. And if you haven't done so, you should definitely try it out on a dive by setting modest trigger time or depth and then exceeding it. It not only tests the function but lets you know what it feels like to be brought up and positioned on your back. After testing one function with a full cartridge you can test the others with a spent cartridge. For instance, after trying it out with a full cartridge by exceeding your trigger time, set depth at 20 feet or something where you can easily swim up on your own and then exceed it. You'll hear the mechanism fire even though the vest doesn't inflate, and after surfacing you can verify that it fired. And then you can test the manual pull loop and pressing the button four times without even being in the water or using a spent cartridge. Those functions are not dependent on depth or time, so all you are doing is verifying that the mechanism fires on demand.

I was just being a wise ass about it not curing cancer, etc. But since I brought it up, I had a prostatectomy nine years ago and remain cancer-free so far. I haven't consulted a physician about the hip, but a neighbor who ended up having a replacement had symptoms much like mine. Anyway, its going to have to wait until late fall. Last year I lost 5 months of the summer waiting for a hole in my leg to fill in after having a different sort of cancer removed and at my age I don't have seasons to skip. That white in the hole is my tibia.

 

[Bill McIntyre]

I think I found your answer. In this video, notice that one side inflates before the other. Also notice the inflation on the surface where the diver starts face down and is rolled onto his back. Granted this video was for the generation 2 vest but I don't think the bag has changed- its just the inflator mechanism that has changed.

 

[cdavis]

Mine's an older one, but I'm pretty sure you would have to actively and carefully balance to stay face down when the unit is inflated. Your center of gravity would be too high for face down to be stable. Can't hurt to try it. Hint on making tests and scewup inflations painless: buy a case of cartridges.

 

[Bill McIntyre]

An afterthought on maintenance. The manual rip cord thing is held inside the pouch with a snap. I never even thought about lubing that snap and recently when I pulled that loop to test the manual inflation I pulled the outside of the snap through the fabric. I don't think I could get it apart without destroying it. I emailed Terry Mass and suggested that he add a mention of that to his maintenance instructions. I think I'm going to stick that handle into the pouch with light thread so it will stay in there but come out if I yank on it.

 

[HooSlayer]

i did get it with a case of cartridges (8). I will conduct my own test on this, face down to face up issue. I can see that the diver in the video gets flipped over, but he was conscious and couldve just leaned or moved his fin to turn over too.

 

[Diving Gecko]

Thanks, another question. So lets say you have the feature where it auto inflates if you don't press the button upon each surfacing. You experience a black out on the surface and end up face down on the surface floating. Upon inflation, will the vest always turn you onto your back from being face down?

as a side note it would be good to have an alarm that beeps to remind you to press the button everytime you surface, does it do that?

Yes, according to Terry it will turn a diver who blacked out on the surface.

The feature you are mentioning is called "surface minder" by Terry. I actually turned it off on mine, too. I know I am not getting the most out of the vest like this but I would very likely forget to press the button upon surfacing. Actually, after a very short time I stopped even looking at the remote. That's how easy it is to get used to wearing it.

No audio signal sadly. Terry said they tried it but the waterproof box muted out any beeper they tried. Many dive computers are the same and for that reason it is not uncommon for freedivers to stick their computer in their hood so they can actually hear the alarms.


Sent from my iPhone using Tapatalk

 

[HooSlayer]

I've come up with another question. Lets say you have surface minder off and black out at the surface and start to sink. If you sink to 6 ft within the first 15 seconds upon surfacing, the vest goes off.

is 15 sec really enough time to sink that far and experience the blackout? Like if you had a few breaths but blacked out and slowly sank, and it took you 20 seconds to reach 6ft, would the vest not inflate then?

 

[Bill McIntyre]

I don't think it would inflate if it took you over 15 seconds to sink to 6 feet. I don't know how likely it is for that to happen. Maybe the guys with competitive freedive experience can tell us. They are more likely to have experience with divers pushing it and blacking out in competition in the presence of safety divers.