DIY PLB Dive Canister Critique

[CuzzA]

Hello All,

I'm interested in hearing some feedback on my DIY PLB Dive Canister. I always carry my ACR ResQLink+ whenever I venture off the beaten path, on my boat and since recently becoming certified I want the device with me at all times anywhere in the world. So when I began to research dive canisters/housings for PLB's I was quite shocked at the price the manufacturers were asking. In fact, it actually struck a nerve they were asking damn near more than the PLB itself. Now, I'm not trying to be cheap, but I also know when I'm getting ripped off and I simply refuse to support someone who is gouging. That being said, I built my own.

It's an obviously simple design. 3" pvc pipe, 3" pvc cap and a 3" pressure test plug. I used two stainless steel bands and Velcro to secure it to my BCD tank webbing. I also tied a bolt snap to it. I used my FoodSaver vacuum to seal the PLB for added protection. The PLB unit itself is water resistant and can withstand a limited amount of time at depth. I submerged the unit in my 7' deep pool for 24 hours and it was bone dry. Of course 7' feet is nothing compared to recreational diving depths.

So again I'm looking for critisim and critiquing of this design. Am I good to go? Going to have trouble with it? Any alternatives? It is rather bouyant so I'm also considering adding some lead to it. Thanks for any advice.

 

[dmaziuk]

Thanks for any advice.

I wonder why the PLB itself has to be dry. I mean, electrical devices don't like water because they get shorts and metals don't like it because they corrode. Neither is a problem if you're immersing in a dielectric liquid. The upside would be that liquid's uncompressible so with your canister full of it you wouldn't need to worry about the pressure differential. (Plus if you use alcohol you'll have something to toast your successful rescue.) Just a thought

 

[CuzzA]

Ok, so fill it with a liquid. Any suggestion as to what liquid? Oil, Bourbon, Vodka? I'm sure if I ever needed it a shot of Bourbon would help calm the nerves.

 

[3D diver]

Mineral oil, apparently...

Hack a $4 LED flashlight into a scuba diving light with a laxative!

 

[dumpsterDiver]

Why not use an old dive light as a cannister?

 

[CuzzA]

Mineral oil, apparently...

Hack a $4 LED flashlight into a scuba diving light with a laxative!

Mineral oil it is. Plus I'd hate to waste alcohol. Lol. Thank you.

Why not use an old dive light as a cannister?

That was a consideration, unfortunately I don't have one, don't know anyone with one and a week long search on Craigslist did not yield any results. But, I will keep my eye out.

I'm a little shocked at the lack of options to take dry objects to depth. I know there are Pelican cases, etc., but my research suggests square O-rings/gaskets aren't very reliable and I'd like to make it very difficult on Murphy. Im surprised someone isn't manufacturing simple dive plastic double o-ring canisters for this purpose.

 

[seeker242]

I wonder why the PLB itself has to be dry.

It doesn't need to be dry. It's completely waterproof, it just can't be subjected to excessive pressure. The waterproof specs are "5m for 1 hr" or "10m for 10 min". Beyond that the gaskets might fail, or maybe not. But, when it comes to lifesaving device, maybe is NEVER a good thing.


@CuzzA

As long as it's not subjected to excessive pressure, that may compromise the gaskets, it will be fine. Speaking as an ACR PLB service technician myself, I can confidently say the pressure is all that matters. If you are going to fill the canister with some other fluid, you should make sure that whatever it is, will not react with or degrade the gasket plastic.

 

[CuzzA]

It doesn't need to be dry. It's completely waterproof, it just can't be subjected to excessive pressure. The waterproof specs are "5m for 1 hr" or "10m for 10 min". Beyond that the gaskets might fail, or maybe not. But, when it comes to lifesaving device, maybe is NEVER a good thing.


@CuzzA

As long as it's not subjected to excessive pressure, that may compromise the gaskets, it will be fine. Speaking as an ACR PLB service technician myself, I can confidently say the pressure is all that matters. If you are going to fill the canister with some other fluid, you should make sure that whatever it is, will not react with or degrade the gasket plastic.

No doubt, "maybe" is not an option with anything scuba related. Given that I have it vacuum sealed I'm confident water will not enter the unit at depth even if the canister were to leak. In fact, I'd be willing to bet the vacuum seal alone would work just fine. However, I wouldn't wager my life on it. Thanks for chiming in.

 

[kwinter]

As for the canister itself, I would suggest you leave the PLB out, stuff some paper towels in it, seal it up, take it down to 100 or 150 feet for a while, surface, and then try to open it up while bobbing in some swells. It will not only tell you if it stays dry, but the big question is whether being under pressure would make it harder to open after the dive.

 

[KeithG]

Why not use an old dive light as a cannister?

depends upon the style. we have a few ikelite rcd-8 monsters sitting around, but they feature a central locking spine. they will swallow anything d cell in size, but not much larger. so they are poor candidates.

any suggestions on specific brands that have no internal obstructions?