PLBs Can Save Your Life

[DandyDon]

do you remember? Or perhaps you still have the instructions?

Sorry, I got mine 4 years ago, and my memory is a joke.

 

[tridacna]

I used to hand-tighten it snugly. After diving, I would struggle to open it by hand. It bothered me that if I ever needed to open it on the surface, I would struggle mightily to get the EPIRB out. I now use a Light Monkey canister which works flawlessly. Expensive but superbly engineered.

 

[Dan]

If my camera or light leaks, it's ruined. If my PLB canister leaks, it gets wet but so what. Take the risk.


Do you ever check the dip stick on your car or just drive until the oil light comes on? Another reason for opening daily is to ensure it opens easily.

On my 1985 M6 yes. But on my 2013 X5, it has oil level gauge on the instrument panel.

I place my PLB1 right after testing it on the liveaboard. So it hasn’t been in the canister for more than 2 weeks. I did check it at depth once and posted the picture here once. Also I calibrated how much o-ring compression I need to put on the lid and open it after a dive to make sure I can open it with my wet hand.

The best PLB1 case is still the one with a latch & hinge like my old $10 camera case that I got from eBay. No unscrewing lid is needed in that kind of case.

 

[Dan]

Yesterday I pulled out my PLB1 canister from my BCD pocket and open it after 6 days of total 20 dives. No problem. All dry inside.

 

[-JD-]

@-JD-

Here’s a video!

Thanks, OOB! Looks like there is a circumferential compression oring which forms the seal on that. I didn't know that the lock ring is separate.

Definately interested to hear your after-action report.

 

[DandyDon]

O-rings themselves are super inexpensive (pennies!) so once we have the size, material, and durometer. I'm hoping he will share the info

He answered my email. Here is the label. Now I do not know anything about what all that means or how to find the same one without having to order 50 (my computers have both used the same o-ring for years thru many battery changes as I didn't want to buy a gross!), but surely someone here will know!

Actually, I started a separate thread, so discussion will probably work better there: https://www.scubaboard.com/community/threads/hdvseatek-o-rings-identified.585033/

 

[Dan]

My new smaller custom made canister 2”ID x 5”IL is finally fabricated. It’s too tight for PLB1. I don’t recommend it to make one. I had to shave some corners out of the PLB1. See the picture, below.

View attachment 523192

Compare to the 2.5”ID x 5”IL

View attachment 523197

Top view of both lids, below
View attachment 523195

Bottom view of both canisters, below
View attachment 523194

Side view of both canisters, below
View attachment 523193

I made the bigger one to fit ACR PLB like the one below.
View attachment 523198

The reason I made the smaller one is because I try to minimize carrying extra dive weight to counter weight of the extra air space in the canister. May be I can just put a small cup of jello on top of the PLB1. One of these cups, below
View attachment 523201

I’ll take both canisters for diving down to 100’ deep next weekend. We’ll see how they perform.

@foob bought my prototype Acrylic canister and it seems to fit well to his ACR, as shown below.

I’m wondering how do you mount this kind of PLB to keep the antenna straight up to the sky for 24 hours. You certainly won’t hold it up by hand all day long while bobbing at the surface, would you?

PLB1 comes with shoulder strap like this, below.

 

[DandyDon]

I’m wondering how do you mount this kind of PLB to keep the antenna straight up to the sky for 24 hours. You certainly won’t hold it up by hand all day long while bobbing at the surface, would you?

PLB1 comes with shoulder strap

My ACR 2881 came with a velcro strap, and I guess the newer ones do as well. Did he remove his for some reason? I think that's a bad idea.

 

[Dan]

I ended up to custom made my own PLB1 canister for that size with some shaving off the PLB1 corners to fit into 2” ID. The cost is also more than any commercially available PLB canister, obviously.

View attachment 525637

Made 40 dives down to 137’ (42m) to meet those Mola Mola (below) and no leak so far.

 

[Backflop]

I found the ffsystem.co.uk PLB container on a different board, but thought that the folks here might appreciate the info as well. It's as an interesting option for those looking for a burly middle-to-higher end option: they're hand machined from solid delrin rod with two stainless latches and two o-rings (one axial seal, one radial seal). Construction-wise it seems pretty similar to the Light Monkey canisters I've seen, and I have no doubt they'll exceed most recreational ranges without a leak. At 100GBP (~$130) each, they seem like a great value.

Note though, that these things are big. At 175mm tall and 83mm diameter (6.9" x 3.3") and 900g (~2lbs), they're more comparable to the McMurdo fast find canister than the HDVSeatek or Custom Divers options. If you've got a 20oz insulated tumbler, they're almost the exact same size. It isn't a tiny little thing you can throw anywhere - it's a planned piece of kit. I thought I'd stuff it into a pocket with my DSMB and spool, but they just barely all fit together into a DGX Horizontal pocket, and are hard to remove once in. This will live on a belt for me, but my dive buddy will likely require convincing to wear hers .

Usable interior dimensions are 122mm deep and 62mm across (4.8" x 2.44"). It fits my PLB1 with the float case on it easily, with room for candy bars, water, keys, cash, and more. Somewhat surprisingly, they're also just about neutral in freshwater - <50g floaty.