New Product/Firmware Suggestion

I have a comment/suggestion/request for any
new dive computer or firmware release coming out
in the future.

It would be very useful to have a F02 50% indicator.
(by blinking the "Nitrox" mode indicator)

The computers have the FO2 50% default mode
which resets the computers FO2 value after a dive.
This is a good thing. However, there is no visible
indication on the display that the dive computer has
gone into this non optimal F02 50% oxygen/78% Nitrogen mode.

What would be really nice and should be easy to do
would be to blink the "Nitrox" mode indicator while in this mode.
This would provide immediate feedback to the diver that his
computer needs to have FO2 reset. It would be noticed
BEFORE the diver hit the water as he was checking is
air pressure.

My wife and I accidentally did 3 dives in this FO2 50% mode
because there are certain conditions that cause the FO2 to be
reset that can be easily overlooked. The most common one being
getting all geared up ready to go and then noticing that your
bungie is still on your tank but under your first stage which
requires removing the first stage.
The drop in tank pressure will cause FO2 to be reset.

The only indication that you have that your FO2 is wrong
is when your PO2 values start to alarm during the dive.
It would have been nice to have had an indication prior to
jumping in the water to remind you to reset FO2.

I believe that if the dive computers had this indicator,
people would be less likely do disable the FO2 50% mode
and would then be less likely to be diving with the wrong FO2,
which would make for safer diving.

This is one of those subtle nice features that could be added
to the many that Aeris/Oceanic already has in their dive computers.

--- bill

With Oceanic you can set it to default to 21% instead of 50%.

Sure you can disable the FO2 50% and then lock FO2 to whatever
% you want. But that isn't the point

Air fills aren't always consistent exact FO2 values and
it would be much better if there was a way to remind the diver
to reset his FO2 for each dive so that his computer is
performing proper calculations.

To me, having this 50%/78% FO2 mode is problematic without
having some kind of visual indicator that the dive computer is
in this mode.

--- bill

If you need a reminder to make sure you are set for the correct %, i'm worried about you. This should be as much a part of your pre-dive regime as checking that your air is on.
IMHO

Oh come on.....
It isn't that I didn't set the FO2, it is that the computer UNSETs it
AFTER I set it. AND the thing that triggers the computer
to unset my FO2 back to 50% is NOT DOCUMENTED in the manual.

Consider the exact scenario that I described earlier.
You are on a liveaboard. Your tank is bungied to the boat
you sample your tank, fill in the nitrox log and sign it,
hook up your reg, gear up, do some preliminary buddy checks,
set your FO2, then you notice that the bungie is underneath
your 1st stage.
This requires removing your first stage. In order to do this you
have to turn off your tank and purge out the pressure.
When the computer sees the pressure drop to 0, it silently
resets FO2 back to 50%. This is not documented in the manual
and there is no indication that this happened.

In another scenario, you did your nitrox analyzing before
lunch, you hook up your reg, turned the gas on to check
your pressure, set your FO2, then turned off the air valve,
then went for lunch.
When you returned, you gear up, start to do your buddy checks,
check your FO2 to make sure it is still set right - it is,
pressure looks good, but after a quick purge and test for
tank pressure, you see your tank pressure has dropped to zero,
because the tank valve was still turned off.
You turn the air back on and do another quick air test.
Good to go; right? Wrong! Unknown to you, your dive computer
just set your FO2 back to 50%.

In another, a helpful buddy or divemaster accidentally turns
your air off instead of on. When you do an air check while
standing on the dive deck, the pressure drops to zero and
your computer will silently reset your FO2 just prior to your dive starting.

There is nothing that I forgot to do or check. I got burned by
an undocumented feature of the divecomputer. While I think
it is probably a good thing to revert back to 50% when the
pressure goes to zero because the person might be changing
out tanks. I think the computer should indicate that it has done this. The computer knows it is in this funky mode and could
easily indicate this without having to add any additional
recurring manufacturing costs to the product.
Its a small feature that could help prevent people from
diving with the incorrect FO2 setting.

--- bill