• Welcome to ScubaBoard


  1. Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

    Benefits of registering include

    • Ability to post and comment on topics and discussions.
    • A Free photo gallery to share your dive photos with the world.
    • You can make this box go away

    Joining is quick and easy. Login or Register now by clicking on the button

Hypothetical - 2 AI transmitters instead of backup SPG?

Discussion in 'Computers, Gauges, Watches and Analyzers' started by Shafqat Ahmed, Jul 12, 2019.

  1. Joneill

    Joneill Loggerhead Turtle

    # of Dives: 100 - 199
    Location: New Jersey, USA
    1,363
    1,113
    113
    For me, what you seem to miss here is we are not talking about equipment that has high failure rates to begin with. Computers and transmitters are quite reliable in 2019. I have actually had 2 SPG related failures but zero issues with computers and transmitters.

    We are also talking about recreational NDL diving here, so in the incredibly unlikely scenario that both of my computers and transmitters were to fail, I'd just end the dive and ascend. As I'm more likely to win the lottery, in the meantime I can dive with higher confidence of not having to ever end a dive early or sit out a day of diving due to an SPG, computer or transmitter failure.

    Therefore, I don't see how that is adding any real complexity to my equipment and I'm certainly not taking on any extra failure modes that I'm not prepared to handle - in fact, I'm better prepared in the event of a failure in my opinion. A transmitter or computer failure on a trip would be pretty much a non-event given the redundancy.
     
  2. KWS

    KWS ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 500 - 999
    Location: SE TEXAS
    4,237
    940
    113
    We are hitting some common ground here. You last paragraph is good. The threat of a loss of a computer is of no real concern because of the second paragraph. Because of the lack of threat from a loss of a computer or transmitter in an NDL situation is not a big deal. that position is what founded the overkill aspect in the discussion. That you dont need a 1000$ backup to survive a NDL nontech dive. I dont think anyone really cares what equipment one dives with, However the idea of,,,,,,,, if you don't have 2 computers you may be risking your life is not one that should be taken seriously and giving merit to saying a second computer is a good idea fosters that. That was the root thought i got when the OP asked the hypothetical question. I got DO I THINK IS IS NECESSARY TO HAVE A COMPLETE BACKUP COMPUTER BASED TANK PRESSURE REPORTING SYSTEM in the event of a computer or xmitter failure. My responce is no that a SPG is all that is needed. My reasoning is I think inline with DIR concepts (not that they are gospel) as much as i dislike saying that but in this case it makes sense. I see nothing preticularly annoying with someone using that configuration so long as they have their alarms turned off on the backup unit. The water gets filled with beeps as it is let alone with backup units doing it also. Ones systems should not interfere with other divers. Everyone takes and mitigates their risks differently for the conditions they dive, so there is no 100% right answer. I look at a computer and say if i hit a rock with the face and it breaks the face and causes a loss what do I do. In that case a second computer would probably work just fine with in the limited constraints of that scenareo, but there are so many more situations that one can not think of. People do not get hurt by things they expect to happen, it is the weird stuff that gets you. at that point it is the cost factor of that backup device that for me is an issue. I once questioned having an SPG on both regs on doubles. Was not expensive but once thinking about what would drive me to need the backup eliminated that option. all cases resulted in end the dive. those cases being having to be isolated manafold because of a rupture etc on the other side. Anything serious enough to have to use such a method would first call for calling the dive.
     
  3. Joneill

    Joneill Loggerhead Turtle

    # of Dives: 100 - 199
    Location: New Jersey, USA
    1,363
    1,113
    113
    But no one here here ever said that you need a $1000 backup computer to survive an NDL dive. Nor did anyone here propose that the idea of,,,,,,,, if you don't have 2 computers you may be risking your life. You are the one telling us that is what we are saying when we are not!

    The op merely asked if diving with 2 transmitters was dumb. The fact is that it is not. It’s not necessary, but if you have the means, it can provide the upside of not ever having to call a dive early or sit out a days diving due to a failure in a non redundant system. To some, like me, that is worth it - to others, maybe not.

    And now you are talking about beeps and alarms as reasons to not use redundancy? I give up as I’ve said all I care to on the second transmitter/computer opinion... :banghead:
     
  4. KWS

    KWS ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 500 - 999
    Location: SE TEXAS
    4,237
    940
    113


    OP asked if it were dum,,,,,,,,, Well; yes ,,,,, Now,,,why did he ask that? (assuming that he is speaking from the view of a new diver,,,,, that is where i got my interpretation of what he was trying to ask. If you say it is not dumb ( or reallty teh smartest approach to the concern) then you are implying or being interpreted as saying it may be a neccesity. If you say it is dumb, then there should be a reason why. Which I tried to give in logic terms. Since teric was mentioned,,,,,, how much is a teric with a xmitter, 1000. pllus or minus???? that is where i got that statement. If you are going to need that sophisticated level of back up there must be a reason why also. to say or imply there is a need is suggesting your life could depend on it. Its not a backup that is in question it is the form of the backup and the liabilities that come with it either seen or unseen.

    Your second paragraph is correct If you can afford it why not. My issue is that with a computer there comes a lot of other stuff that goes beyond the simple aspect of getting a PSI reading that may deter the dove more than it will help it. In the rec world those issues center around nitrox and alarms and redundant things to maintain such as batteries and the quality of people doing the work. With shearwater's prior to teric. (I do not own one and am not familiar with teric) it is a very simple process relying on tools that are in everyones pockets to change a battery. There are no precision o-ring lands for the o ring to be in. the chance of a on o-ring failure due to a battery change by a diver on the beach is rather small. That can not be said for many other brands. I can tell you I played Heck trying to get a good change on my aeris t3 AND t3 ELITE, I had to go to several shops to get a tool to do it with also. Hence the user friendly view I have. I have see divers slip and fall on their dive watch. It looks fine but it leaks on the next dive. Point is that if you can not guarantee to be able to cover ANY unforseable incident that may effect your puter, then you need a backup and hopefully in some form that is not prone to the same damaging incident.
    A xmitter is exposed because of its mount location,,,,,,,,,,a SPG is not so much. the xmitter (in reality) is solely a SPG in a non protected location. Locatoin is a contribing factor to a potential failure. BUT it is a factor that can be controlled. It is not so far fetched to have your tank moved or someoneelse moving tanks and you tank falls in the process hitting both exossed xmitters . Then 3 weeks later they both fail. That is not to say that tat could not happen to the SPG however the SPG is often shielded by other items of your kit. Its a game of craps and 7 is more frequent than a 4 to roll.
     
  5. caruso

    caruso Banned

    # of Dives: 200 - 499
    Location: Long Island, NY
    1,663
    1,190
    113
    When I spoke about using a coin to remove the cover, and it being as easy as changing a TV remote battery, I was referring to the transmitter not the computer/receiver. It's my understanding most transmitters have an easy to remove cover. Removing the battery cover from the receiver/computer on my Oceanic VT Pro is easier with a basic inexpensive tool which is like a flat handle with two prongs that insert into 2 holes to assist in rotating the bezel, but it can be done with a pointy screwdriver or something similar.

    I'm having difficulty wrapping my head around this statement, could you clarify further please?

    Wow all those transmitter failures you have had, all these divers slipping and falling on their dive computers and breaking them so they fail on the very next dive. You might want to consider taking up knitting.Then again, those needles can be rather long and sharp. Never mind!
     

Share This Page