accident statistic for Mares Horizon
- Thread starter Bartlomiej
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Sorry, but you’re wrong. If you think like this you should not be diving any form of rebreather and should stick to open circuit within NDLs.
The Horizon is a safe unit. Note that you CANNOT BUY ONE WITHOUT TRAINING. There’s a reason for this, your death through ignorance affects the rebreather manufacturers reputations. If you buy one second hand and don’t seek adequate training before you dive it then you’re plain suicidal.
Sorry to be so harsh, but enough people have died doing this over the years and the whole diving community doesn’t need more statistics.
There is no such thing as a recreational rebreather. Rebreathers are all highly technical and need considerable skills and training.
Would also like to add some useful comments about "recreational" SCR (**semi-closed rebreathers)...
Was diving a few weeks ago in a very remote location at the very north of Scotland. High pressure oxygen simply isn't available there unless you do a one-day round-trip to pick up large cylinders and have a booster.
On the dive boat a person was diving with one of the Hollis "stormtrooper" SCRs which made perfect sense for the type of diving they do up there: shallow diving down to about 30m/100' using nitrox with a lot of photography.
As a rebreather diver, I'd traditionally been very sceptical of SCRs which seem to have all the drawbacks of a "proper" rebreather but without any benefits. I couldn't have been more wrong
If I was staying there for a couple of weeks, I would really have struggled with oxygen supplies. In this location there's not much deep diving (it's very deep, but there's not so much nice stuff to look at and there's no wrecks), so an SCR really comes to the front for the benefits of a rebreather (quiet, long bottom times, no gas anxiety, warm humid air, lighter than a twinset) without the supply problems.
The Mares Horizon will nicely fit that role.
** For people not familiar with a Semi-closed rebreather, they use a breathable nitrox mix which is injected at a constant rate and "leak" gas out. Your exhaled breath goes through a carbon-dioxide scrubber. This means that the gas inside is being replaced so the oxygen levels don't drop. Rather than simply breathing your air and blowing it out as with open circuit, an SCR will extend gas usage by many times. Hence a small 5 or 7 litre cylinder will last maybe 5 hours.
Was diving a few weeks ago in a very remote location at the very north of Scotland. High pressure oxygen simply isn't available there unless you do a one-day round-trip to pick up large cylinders and have a booster.
On the dive boat a person was diving with one of the Hollis "stormtrooper" SCRs which made perfect sense for the type of diving they do up there: shallow diving down to about 30m/100' using nitrox with a lot of photography.
As a rebreather diver, I'd traditionally been very sceptical of SCRs which seem to have all the drawbacks of a "proper" rebreather but without any benefits. I couldn't have been more wrong
If I was staying there for a couple of weeks, I would really have struggled with oxygen supplies. In this location there's not much deep diving (it's very deep, but there's not so much nice stuff to look at and there's no wrecks), so an SCR really comes to the front for the benefits of a rebreather (quiet, long bottom times, no gas anxiety, warm humid air, lighter than a twinset) without the supply problems.The Mares Horizon will nicely fit that role.
** For people not familiar with a Semi-closed rebreather, they use a breathable nitrox mix which is injected at a constant rate and "leak" gas out. Your exhaled breath goes through a carbon-dioxide scrubber. This means that the gas inside is being replaced so the oxygen levels don't drop. Rather than simply breathing your air and blowing it out as with open circuit, an SCR will extend gas usage by many times. Hence a small 5 or 7 litre cylinder will last maybe 5 hours.
With a CCR in this kind of situation (no boosted oxy, shallow dives), you can just use any locally available tanks and SM a full air dilout and a whatever-pressure-u-can-get oxy and no need to travel with your tanks.Would also like to add some useful comments about "recreational" SCR (**semi-closed rebreathers)...
Was diving a few weeks ago in a very remote location at the very north of Scotland. High pressure oxygen simply isn't available there unless you do a one-day round-trip to pick up large cylinders and have a booster.
On the dive boat a person was diving with one of the Hollis "stormtrooper" SCRs which made perfect sense for the type of diving they do up there: shallow diving down to about 30m/100' using nitrox with a lot of photography.
As a rebreather diver, I'd traditionally been very sceptical of SCRs which seem to have all the drawbacks of a "proper" rebreather but without any benefits. I couldn't have been more wrong
The Mares Horizon will nicely fit that role.
** For people not familiar with a Semi-closed rebreather, they use a breathable nitrox mix which is injected at a constant rate and "leak" gas out. Your exhaled breath goes through a carbon-dioxide scrubber. This means that the gas inside is being replaced so the oxygen levels don't drop. Rather than simply breathing your air and blowing it out as with open circuit, an SCR will extend gas usage by many times. Hence a small 5 or 7 litre cylinder will last maybe 5 hours.
Of course, front and SM units are more "friendly" but it is fine with BM units and anyway, it won't be bulkier than a Mares Horizon.
TheCoolBeans
Contributor
I learned a valuable life lesson a few years ago…
I was travelling up an escalator about to cross a road in Beijing, right near the top I looked to my right and saw i was within arms reach of an electricity pole, it was the top and it was like a birds nest of angry sounding buzzing crackling cables.
I spoke to my Chinese friend and mused; “wow that’s really dangerous, what if someone reached out and touched that? They might die?!”
She replied;
“Just don’t reach out or touch it and you’ll be fine, We learned this when we were children”.
In the situation with the Mares Horizon, just don’t turn the Deco tank on, until you are at the right depth?
It’s really no different to accidentally switching to the wrong gas on OC as far as I can see.
Just don’t do dumb stuff that might kill you.
I was travelling up an escalator about to cross a road in Beijing, right near the top I looked to my right and saw i was within arms reach of an electricity pole, it was the top and it was like a birds nest of angry sounding buzzing crackling cables.
I spoke to my Chinese friend and mused; “wow that’s really dangerous, what if someone reached out and touched that? They might die?!”
She replied;
“Just don’t reach out or touch it and you’ll be fine, We learned this when we were children”.
In the situation with the Mares Horizon, just don’t turn the Deco tank on, until you are at the right depth?
It’s really no different to accidentally switching to the wrong gas on OC as far as I can see.
Just don’t do dumb stuff that might kill you.
OP
Bartlomiej
Registered
I am during training, SSI materials online training (English version) has a lot of errors and understatement. It is my first SCR/CCR training and during reading materials, I lose hope that it was a good choice to training on this unit. I completely agree with you that proper training is essential of saving diving, but provide materials have errors and unit has some corner case (which are not emphasized in training) which could kill "recreational reb diver".
In your training it's very clearly said that you shouldn't be opening the deco gas untill you are doing the gas switch.
If you go diving OC with your valve closed you're dead too. It's basically the same thing.
Or if you do an incorrect gas switch, you're in the **** as well.
One of your statements confuses me though.
'But hot nitrox with 12 bar also go to 1st of the bottom tank and in 2nd stage of the bottom tank will be also higher oxygen mix. The suggested deco mix is 70%, so if you will be above 12m you will be in great trouble.'
But won't it just add the 70% mix at 5l/min to your loop with the amount that's left in your manifold?
It's not like your ppo is gonna go insane instantly..
Normally the EAV on the horizon will average about 3,5l per minute extra, since the 5l/min in your loop will never be enough to sustain the loop completely.
So if you have a higher mix,THE EAV just won't add more gas and you might get a slightly higher mix, but it's not like oc where you'll be breathing 70% instantly.
So in that case you just close your deco tank, and you might get a bit higher mix very shortly, but it should be fixed really quickly because there will only be a minimal amount of 70% mix in the manifold anyway. The bottom gas should equalise the percentage in a matter of seconds.
I don't know the exact size of the manifold volume, but it should equalise in + - 10 seconds.
It is true though, that if you'd go straight on bailout at depth with the deco tank open, using the BOV that you'd be dying very probably,
but this is ofcourse assuming that you're ignoring EVERYTHING the machine is trying to tell you or your entire training.
and even in that case you still have the normal second stage with a loop regulator you could just use from your bottom gas. Just purge it before putting it in your mouth and you'll be straight on your 32% mix
So you still have a possibility to safely bailout in that case.
another thing: The pre-jump check on the controller asks you specifically to close the bloody tank after measuring the oxygen content.
Literally : Close DECO TANK: PRESS ENTER TO CONTINUE.
Honestly, they've made it pretty idiot-proof in my opinion.
If you go diving OC with your valve closed you're dead too. It's basically the same thing.
Or if you do an incorrect gas switch, you're in the **** as well.
One of your statements confuses me though.
'But hot nitrox with 12 bar also go to 1st of the bottom tank and in 2nd stage of the bottom tank will be also higher oxygen mix. The suggested deco mix is 70%, so if you will be above 12m you will be in great trouble.'
But won't it just add the 70% mix at 5l/min to your loop with the amount that's left in your manifold?
It's not like your ppo is gonna go insane instantly..
Normally the EAV on the horizon will average about 3,5l per minute extra, since the 5l/min in your loop will never be enough to sustain the loop completely.
So if you have a higher mix,THE EAV just won't add more gas and you might get a slightly higher mix, but it's not like oc where you'll be breathing 70% instantly.
So in that case you just close your deco tank, and you might get a bit higher mix very shortly, but it should be fixed really quickly because there will only be a minimal amount of 70% mix in the manifold anyway. The bottom gas should equalise the percentage in a matter of seconds.
I don't know the exact size of the manifold volume, but it should equalise in + - 10 seconds.
It is true though, that if you'd go straight on bailout at depth with the deco tank open, using the BOV that you'd be dying very probably,
but this is ofcourse assuming that you're ignoring EVERYTHING the machine is trying to tell you or your entire training.
and even in that case you still have the normal second stage with a loop regulator you could just use from your bottom gas. Just purge it before putting it in your mouth and you'll be straight on your 32% mix
So you still have a possibility to safely bailout in that case.
another thing: The pre-jump check on the controller asks you specifically to close the bloody tank after measuring the oxygen content.
Literally : Close DECO TANK: PRESS ENTER TO CONTINUE.
Honestly, they've made it pretty idiot-proof in my opinion.
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