Ordering two BM O2ptima's with Nerd 2's need help with Options

[Dusty123]

For me if im task loaded doing something with my hands I tend to notice the handset before the nerd even know its in my eye. My eyes are just focused literally on what im doing and my wrist is in that plane of focus the nerd is not. Now the nerd is great when just cruising along. I wonder for an alarm if obnoxious blinky leds would get my attention faster than the color changes on the nerd?

 

[tbone1004]

For me if im task loaded doing something with my hands I tend to notice the handset before the nerd even know its in my eye. My eyes are just focused literally on what im doing and my wrist is in that plane of focus the nerd is not. Now the nerd is great when just cruising along. I wonder for an alarm if obnoxious blinky leds would get my attention faster than the color changes on the nerd?

NERD3 needs to have haptic feedback. I think it's coming with the Teric and Peregrine that have it, but the blinky LED's tend to get washed out in good viz/bright sun than the NERD screen

 

[Dusty123]

I could could see that everything is hard to see at the surface

 

[DiveTucson]

There are pros and cons with both. If I was planning on getting a CM unit as well down the road I would do the NERD controller and Petrel as a monitor for the BM unit.

Then on the CM unit you would have the NERD controller and the standard HUD. Nothing tying off to your wrist. Except a stand alone backup.

This is the most common setup on the CM with students across the board. I would also have a discussion with your instructor as well.

 

[JahJahwarrior]

CM dives should have the HUD blinky lights attached, but many of them hide it by stuffing it away, so they can retrieve it if there is a discrepancy to see the 4th cell.

In the ocean, shallow, I don't know if I could see the blinky HUD lights anyways, and a NERD is in my future for sure. At that point, I will use NERD as controller and the HUD as the HUD and my old shearwater controller as a backup in my toolbox in the car. There's probably not many looking to buy used handheld controllers so it would be better to go NERD from the start to save money, but in a class I do understand if the instructor wants to see your handheld to verify po2.

I don't foresee any huge issues with going to low setpoint in an emergency without a BOV. If you are adding buoyancy, you can crush the lungs and evacuate them, and it might be faster to reach back and turn off o2 bottle instead of going through setpoint menus.

A cave filled lp27 dil bottle is 35 cubic feet of gas, a lot more than you can get in the aluminum bottles. O2 you don't get that high of pressure, but in the ocean the additional ballast is probably nice. I haven't used my aluminum tanks since I picked up the steels. But be careful, there is another similar volume steel that is skinnier and longer, perfect for most other rebreathers. You don't want that one.
Bailout tanks for ocean diving, al40's are real popular. Sidemounting them just helps get them out of the way.

 

[stuartv]

unconventional only because it's a relatively new concept, though one Revo has had available for years. What does having the controller on your wrist do that's "better" than in your face?

Allows you to see it easily after you bail?

what are you doing with the controller when it's out of your mouth? Bailout, switch setpoint to low, use the Petrel on your wrist for rest of dive

Switching the SP AFTER bailing sounds a lot easier on my wrist than on the loop that is no longer in front of me.

I'll be "doing things" on the wrist unit after I bail anyway - like changing it to OC/BO mode. Changing the SP there sounds easier.

I love my NERD2! But, I am perfectly happy having my controller on my wrist. If I ever have to bail, I don't expect (or want) to look at my NERD again during the rest of the dive.

That said, I should make it clear that I am still a newb on CCR (less than 100 hours), so what seems "good" to me now may be different that what seems good after a couple hundred more hours...

 

[tbone1004]

@stuartv it depends on what you are using as your primary means of decompression tracking for how often you have to pull it down to look at it and change it. If the NERD is not your primary means of deco tracking if you have to bail out, then you bail out, get sorted out, pull the loop down and change the setpoint, then finish the dive on your wrist.
There are pros and cons to both, but with the CM in particular working much better with the NERD and the intent to purchase anyway, then I'd make it the controller so you can remove the wrist if you don't want it.

 

[kelemvor]

NERD3 needs to have haptic feedback. I think it's coming with the Teric and Peregrine that have it, but the blinky LED's tend to get washed out in good viz/bright sun than the NERD screen

Might be interesting feeling vibrations in your mouth...

 

[stuartv]

@stuartv it depends on what you are using as your primary means of decompression tracking for how often you have to pull it down to look at it and change it. If the NERD is not your primary means of deco tracking if you have to bail out, then you bail out, get sorted out, pull the loop down and change the setpoint, then finish the dive on your wrist.
There are pros and cons to both, but with the CM in particular working much better with the NERD and the intent to purchase anyway, then I'd make it the controller so you can remove the wrist if you don't want it.

This is probably just more of my inexperience talking, but it seems like even with a CM, I'd want a NERD and a wrist controller-or-monitor. I wouldn't do a NERD and blinky-light HUD any more than I would do the same with my rEvo. And if I'm going to have a NERD and a wrist unit, I am unclear on why being a CM makes it preferable to have the controller be the NERD.

If the CM were my BOB, then I guess I could see having a NERD as the controller and no monitor. REALLY speaking from ignorance on that, though.

I especially don't like the idea of a NERD and any other HUD because I have gone to using an optical viewfinder on my camera rig. I don't think I could get the VF up to my mask if I had a NERD/HUD on both sides of the DSV.

 

[tbone1004]

@stuartv with the chest mount it is designed to be unclipped and pushed in front of you. Minimizing cables running from the unit to your arm is really nice with sidemount rebreathers.... If I were running it as a CM and wanted redundant monitors I'd have NERD controller and blinky HUD so the unit wasn't tied to my body with any wires that I'd have to remove.
Blinky HUD would be under the NERD flush to the dsv/bov for me. Irritating with an OVF, probably but that's a different use case.