Operating Depth of SPG

[cerich]

It would sure be nice of the manufacturers would just put the depth ratings on the face of the gauge like watches. Implosions can be pretty dangerous and there is no way to know if success with one gauge holds true with every maker and model.

There was a story floating around in the days of custom Plexiglas camera housings that a guy lost some fingers when one imploded. I can't be sure it really happened but sure find it believable.

implosions are loud...., I imagine most of us that are or have done dives to those depths should know the risks. I simply stopped using spg's on my stage and deco bottles when I was doing that type of dive. Problem solved. I know how much gas I put in and checked before the dive, so barring some unnoticed problem things worked out just fine.

 

[Akimbo]

Well, I know that the standard 2.5" SPGs have been routinely carried on dives from 3 to 400 feet.

speaking from personal experience, I have had plastic spg's have the face face bend in and PIN the needle at depths below 350 and have had one implode at a little over 400.

I've never and most likely will never get deep enough for that to happen with a Brass and Glass SPG.

The problem is not knowing how close to the limit we are. There can be a lot of variation between manufacturing tolerances, constantly changing models, and design changes. We could be 5' or 200' from failure. Just because a housing has been to a depth repeatedly, does not mean it will not implode at the same depth due to cyclic stress or getting accidentally hit on a rock. Given that most products are designed with a least a 2:1 safety margin, it makes sense that catastrophic failures would start to occur in the 350-400' range.

 

[cerich]

busting thru 400 with deeper stuff in mind I worry about HPNS more, I have had spg's, lights and even a computer implode.

That is the nature of that beast.

 

[Akimbo]

busting thru 400 with deeper stuff in mind I worry about HPNS more, I have had spg's, lights and even a computer implode.

That is the nature of that beast.

It certainly is not the nature of the beast in the manned submersible, ROV (Remotely Operated Vehicle), and saturation diving industries where 400' is not deep at all. Implosions are extremely rare and usually results in some engineer getting canned or a manufacturer getting black-listed. Checking depth ratings on equipment is about as basic as checking O2 levels.

You should be very worried about HPNS hits if you are diving well beyond 100 Meters without a chamber, and preferably a bell system.

 

[cerich]

It certainly is not the nature of the beast in the manned submersible, ROV (Remotely Operated Vehicle), and saturation diving industries where 400' is not deep at all. Implosions are extremely rare and usually results in some engineer getting canned or a manufacturer getting black-listed. Checking depth ratings on equipment is about as basic as checking O2 levels.

You should be very worried about HPNS hits if you are diving well beyond 100 Meters without a chamber, and preferably a bell system.

these depths have really only opened up to technical divers in the last few years, it wasn't long ago when we could easily list off the majority of "tech" divers doing sub 400 dives.

Certainly you bring up a valid point regarding ratings