Transmitters on Short Hoses?

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Many tech instructors now accept "transmitters only" for their courses.

That is certainly their choice assuming it meets their specific agency standards. When I was diving tech it didn't meet my standards. Heck, diving rec it doesn't meet my standards. But that's just me. I'm picky like that.
 
I have a question. The pro to having a transmitter and SPG is redundancy, is there a pro to only having one or the other?

I don't care how anyone else dives, but is the one hose amongst all the others really "that bad"?

Not trying to stir the pot, I'm honestly curious.
 
I have a question. The pro to having a transmitter and SPG is redundancy, is there a pro to only having one or the other?

I don't care how anyone else dives, but is the one hose amongst all the others really "that bad"?

Not trying to stir the pot, I'm honestly curious.

This has been debated on other threads. To summarize those who don't have a backup SPG will argue that having one adds another point of failure. The high pressure hose, the SPG and a handful of o-rings. In theory yes this is true. In practice it is miniscule. If a high pressure hose, SPG or o-ring is going to fail it will do so upon pressurizing on the boat. These things just don't fail mid-dive. On the other hand a transmitter battery can fail mid-dive. In my opinion that is a far more likely scenario than my SPG failing mid-dive. This is why I've kept my SPG. It is tucked away and clipped off on my left waist d-ring. I don't even know it's there ... unless I need it.
 
This has been debated on other threads. To summarize those who don't have a backup SPG will argue that having one adds another point of failure. The high pressure hose, the SPG and a handful of o-rings. In theory yes this is true. In practice it is miniscule. If a high pressure hose, SPG or o-ring is going to fail it will do so upon pressurizing on the boat. These things just don't fail mid-dive. On the other hand a transmitter battery can fail mid-dive. In my opinion that is a far more likely scenario than my SPG failing mid-dive. This is why I've kept my SPG. It is tucked away and clipped off on my left waist d-ring. I don't even know it's there ... unless I need it.

That was my assumption, thanks.
 
That's a silly question and you know it. Of course I didn't. An SPG failure is far less likely than a transmitter failure. Transmitters are definitely more reliable than they used to be. I've never lost connection to my Perdix AI. However, you are still dependent upon one electronic device with one battery ... the transmitter. That is a single failure point with a failure potential high enough that it warrants redundancy. However, that is just my opinion. Dive however you wish to dive.
Oh boy, another issue that has been beaten to death on SB. There are many who agree with you and many who disagree.
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I discovered this configuration a while ago on the board and have been diving this for a few dives and I am actually quite happy with it.
That's pretty slick. I have to run hoses on the rebreather for the transmitters due to packaging constraints. Something like that would make setup easier. Where did you find the high pressure T-fittings like that? Might be worth a try.
 
If we were to only discuss things once around here the interaction and chance to advance new ideas would be more limited. I will offer my experience and opinion here regarding redundant pressure gauges.

On my current dive trip, I've been diving three tanks, five days a week since Christmas. This is in OW with a deco obligation. I plan for at least an hour of gas after my deco is cleared. That is a little misleading because I may take an hour to clear a 20 minute deco because I dive the reef not the stops. If I needed to exit sooner for some reason then my extra gas would be closer to two hours at shallower depths. I like to exit with a surface gf of 50% or less.

I use transmitters on my left and right tanks and an spg on my stage. My dives are 4 hours long so I have experienced a transmitter battery getting weak mid dive. When this happened it started dropping out signal intermittently. I knew where my pressure was so I continued to dive but used the faulty side more heavily. I left a bit more reserve in my stage which I usually breathe down to near empty. I continued the dive. Later in the dive I got a reading on the weak transmitter and recalibrated where it was in my head. It wasn't very different from what I expected. The dive went on as normal and near the end the transmitter began acting normal again. I changed both batteries before the next dive.

On another dive, I was gearing up and checked the pressure on my stage and it read 3,400 in an AL80. I decided to check it with another spg from my kit. As I was handling the regset I realized that what had happened was the screw that secures the numerical faceplate on my ScubaPro spg had backed out and the plate was able to rotate, giving a false reading. If that had happened underwater I doubt I would have noticed and may have had an unpleasant but manageable surprise.

These experiences don't make me suddenly start diving with two gauges on every tank. I have redundant gas and conservative gas planning that covers any number of unexpected surprises with a single tank of the three I carry.

I don't use button gauges. They are unreliable and easily catch onto things they shouldn't. When I put them on top of the reg, they would sometimes catch in my shoulder d ring and were difficult to get back out.

That's my experience and my decisions. This horse isn't dead just because we have discussed the topic before. If we kick it in a circle a few times, then perhaps the emoji would be justified. IMO of course.

Happy diving.
 
https://www.shearwater.com/products/swift/

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