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you would need a lefty regulator for it to work on the left side....
Shearwater NERD 2 "for OC Divers"
- Thread starter kelemvor
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you would need a lefty regulator for it to work on the left side....
Now that I think about it, what do CCR divers do if they are using a NERD and they have to go off the loop? Specifically, CCR divers who do not have a BOV.
If you don't have a BOV and you go off the loop, then that would mean you can no longer see the NERD, right? So, does the NERD then just become a paperweight? Not only no use for the rest of the dive (assuming you stay off the loop), but not really of any use if you were to want to do another dive, since the NERD would not have the correct residual inert gas tissue info, right?
If you don't have a BOV and you go off the loop, then that would mean you can no longer see the NERD, right? So, does the NERD then just become a paperweight? Not only no use for the rest of the dive (assuming you stay off the loop), but not really of any use if you were to want to do another dive, since the NERD would not have the correct residual inert gas tissue info, right?
When you go off the loop, you have to switch both the controller and the NERD to bailout (OC) mode so that doesn't happen. They are both set to your OC bailout mix, so you keep accurate deco information. Also, you often can go back on the loop after bailout if you fix the problem, so it needs to be accurate.
But, what happens if you bailout and then have a gas switch to an OC deco gas? (again, in the case that you don't have a BOV and you can't get back on the loop) How do you see your NERD in order to do the gas switch?
It's not hard, you just grab the loop and hold the NERD up to your mask. Easy to read and push the buttons. It's basically a small Petrel, same controls, etc...
It combines your backup deco information with your HUD. The JJ comes stock with a modified Petrel controller and a HUD, which blinks your PO2 at you with a standard code. They are run by separate boards and power supplies, so it's unlikely that you will be forced off the loop by an electronics failure. In that configuration, most people have another dive computer as a standalone, but since it isn't connected to the CCR, the only way it can approximate deco is if you tell it what PO2 you are running, or what mix if you bail out.
When I got the NERD, I got rid of the standalone. The NERD has the advantage of replacing the HUD with something that is much better for showing me my PO2, as well as lots of other information. It also replaces the standalone, and since it's getting PO2 readings from the cells, it's going to have accurate backup deco information without having to manually tell it what you are breathing if you are on the loop.
If you are carrying more than one bailout tank, you would have each of those gasses programmed into the NERD and the controller, so that when you bail out or switch to a richer mix during deco, you can set both of them to know what you are breathing.
Another cool thing about the NERD is the compass. It's nice to just glance forward and have it tell you the heading hands free, wherever you point your head.
As a rec diver something like this is appealing but just way overkill.
I'd be happy with even some kind of super lightweight alarm LED near my mask just to indicate something has gone wrong and I need to look at my primary computer (Configurable options, perhaps: NDL at < X min, Depth > X, air < X bar if it's an AI computer).
I suspect the cost of just transmitting data like that adds too much expense - I'm not sure what kind of ultra small LED / wireless receivers exist like this.
I'd be happy with even some kind of super lightweight alarm LED near my mask just to indicate something has gone wrong and I need to look at my primary computer (Configurable options, perhaps: NDL at < X min, Depth > X, air < X bar if it's an AI computer).
I suspect the cost of just transmitting data like that adds too much expense - I'm not sure what kind of ultra small LED / wireless receivers exist like this.
The problem is radio waves don't travel underwater. They use low frequency and a coiled antennae (to make them longer) to achieve some 4-5 feet range from a thumb-sized transmitter with a regular battery. The whole setup ends up being quite a bit bigger than just a led in the mask.
Are you saying that a device that receives a RF signal and turns on an LED would be too big to conveniently put in or on a mask? The NERD2 does all that and is a full-on computer with a full computer display built-in. It seems like they could probably make it a LOT smaller if it only needed to power a warning LED occasionally. Especially if it had something like a USB port to plug into for programming it (i.e. pair it to a dive computer), so that it didn't need its own buttons or a display.
Or are you saying that adding a transmitter antenna to a dive computer would make it too big?
That's what I figured - and cost accordingly. Not sure what the smallest underwater receiver possible is. You could potentially use existing ones that pair with AI transmitters to trigger on low air alerts. (Based on the existing FCC ranges for VLF/ULF, MH8A, etc)
Maybe we should prototype this @stuartv
Wow, I don't use the phrase "gear solution to a skills problem" often, but all that tech to feed tank pressure, NDLs and depth into your mask?
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