Backup Pressure Gauge ... thoughts?

[scubabes]

I'm in need of a backup pressure gauge (we have AI dive watches), and although I trust the watch about 99%, I think it's smart to be redundant on air pressure. I want something small, but I'm looking for recommendations: brass? metal? boot or no boot?

Any thoughts on the following:

Dive Rite Compact SPG
Oceanic Pressure Gauge: Oceanic Pressure Gauge reviews and discounts, Oceanic

I'm also open to other suggestions. I don't want to spend a small fortune, but I want to make a smart purchase. Your input is appreciated!

Bes

 

[charlesml3]

There is very little difference in pressure gauges. Just get one that's big enough for you to read from wherever you'll be clipping it.

-Charles

 

[Gombessa]

If it's a backup, its job is to be reliable. I'd suggest just staying away from cheaper designs with plastic faces (a lot of us like larger, 2" face brass and glass spgs without a boot), but honestly, even that would probably be fine. Note that you're probably not even saving any money with a less sturdy spg - Scubatoys sells plastic SPGs for $59 and brass/glass ones for $58, so why not get the brass?

 

[firstdive2005]

I have always had an computer with transmitter(tmt). But I always felt the need to have extra precaution. I hooked up a halcyon spg. I dont clip mine to my waist ring, I clip mine to my inflator hose. I just have access faster and I can see it better. Now that I'm going into different areas of diving, my instructor has pointed his gnarly finger at my tmt and grunted must go. Bottom line is I know there are ok, good and very good products out there. At the time I bought mine I was influenced that halcyon is one of the best.

 

[TravisD]

Get the one that'll fit nicely in your Save-a-dive kit.

If it's on the rig full-time, and one of them stops working, which one do you believe?
If you don''t have a backup you should be able to detect this anyway. If it's reading too low, you end up going up sooner than later (safe). If it reads too high (basically, stops going down) then you should notice this when checking your air. Again, you thumb the dive at that point and surface safely.

If the backup is on the rig all the time you now have more o-rings and another hose as failure points. In any case, once one the gauges no longer agree on your air, you're thumbing the dive anyway, right? (which one is correct?)

If it's in your S-A-D box then you can swap it out between dives and be back in the water. It can also get your buddy back in the water in the event that their normal gauge goes toes up. Should only take a minute to unscrew the transmitter and screw in the gauge hose.

Also, have you checked to make sure that your 1st stage reg has a second HP port?

 

[Peter_C]

Get the 24" hose and a stainless bolt snap. If you are talking brass and glass there is not a lot of difference in the manufacturers name on the unit.

HOG Brass and Glass SPG

 

[redacted]

Get rid of the unreliable (and expensive) primary gauge and replace it with something with adequate reliability (and cheaper).

 

[Web Monkey]

I'm in need of a backup pressure gauge (we have AI dive watches), and although I trust the watch about 99%, I think it's smart to be redundant on air pressure. I want something small, but I'm looking for recommendations: brass? metal? boot or no boot?

If you're diving with a computer an SPG is pretty much useless for anything except seeing if you're out of air, which you can also determine with the question "am I still breathing".

You would not have the necessary data to calculate your remaining bottom time unless it was the first dive of the day and you knew your maximum depth, dive time, and had tables in your pocket. For a no-deco recreational buddy dive, I'd suggest staying near your buddy and calling the dive if the computer malfunctions, and sharing air to the surface if you run out.

A spare spg is nice to bring along, but I'd leave it in your bag until you need it. It's just extra "stuff" and defeats the purpose of having a wireless computer, which is to get rid of extra hoses.

Terry

 

[Peter_C]

The gauge also provides an easy way on your rig setup to see how much pressure you have. Allowing you to also do a check for pressure changes while sucking deep on your regs BEFORE getting in the water. This makes sure your regs are working and that your air is in fact on. An AI will not react fast enough for this important check.

AI's largest failure point is the signal between the sending unit and the wrist mounted computer. The wrist unit will function with or without the air integration. The pressure gauge could possibly allow you to finish your week of diving. Computer failure is immediate grounds for a safe ascent to the surface.

My last failure was a Halcyon pressure gauge, but it barely bubbled. Since I do use an AI computer I simply removed the pressure gauge and went for a second dive.

 

[fnfalman]

The gauge also provides an easy way on your rig setup to see how much pressure you have. Allowing you to also do a check for pressure changes while sucking deep on your regs BEFORE getting in the water. This makes sure your regs are working and that your air is in fact on. An AI will not react fast enough for this important check.

You mean I can't just twist the valve handle all the way open to verify that my air is on?