DryFob XL: Affordable Canister for PLB

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Shelby Township, MI USA
# of dives
500 - 999
This is a review of the DryFob XL (https://dryfob.com/product/dryfob-xl-waterproof-plb-container/), a waterproof canister designed to keep items dry down to 100 meters or beyond, sized to contain PLB's and other such items of similar size.

This is somewhat long (surprise!). I start with a brief description of what I'm using it for, and other solutions I've tried. I've put subheadings in, so feel free to skip to the review details in the second post.

Why Is This Needed?

For many, a Personal Locator Beacon (PLB: Emergency position-indicating radiobeacon - Wikipedia ) is a desirable part of their SCUBA emergency equipment. The majority of these devices combine a GPS with a radio transmitter designed to communicate with satellites in orbit anywhere in the world. For me, I acquired a PLB before I went on a liveaboard in Egypt: it is not unknown for such liveaboards to sink. But even in the United States, it's not unknown for divers to end up floating at sea, so once having spent the money, it would be very useful to be able to have my PLB with me.

The problem is, these devices are not designed for SCUBA divers. Even the best of them are only waterproof to about 30 feet, and most are 15 feet or less -- more splashproof than waterproof. There is one such device (the Nautilus: Nautilus Marine Rescue GPS - Free to use, Diver Rated to 425 ft. | Nautilus LifeLine ) that is rated to below 100 meters, but it works differently: it sends signals to a nearby boat in line of sight, rather than satellites in orbit). There are advantages and disadvantages to each. This review isn't about PLB's themselves; but suffice it to say that for many people, the satellite-based EPIRB PLB better fits their needs. But they're only barely waterproof.

So if you want to carry such a PLB, you need a way of protecting it while you're deep underwater. After all, the most likely time to need a PLB is when you come up from a dive and the boat is nowhere to be seen. If you can't bring it with you throughout the dive, it rather defeats the purpose of having it in the first place: it does you no good if it's left behind on the boat while you do the dive. So how do you accomplish that?

Bad Idea: Cell phone bag

My solution for this was simple: use a flexible drybag designed for cell phones. This seemed like a decent solution: it was cheap, it was designed to keep water out of sensitive electronics, and even if it didn't work perfectly, the PLB itself was waterproof enough to keep water out even if the bag leaked a bit. So why not?

One kind of obvious thing was that the water would be pressing in on the device through the plastic bag. Could that activate the button? It seemed like this would be unlikely: the PLB I use, an OceanSignal PLB1) has a protective cover over the button, as well as a neoprene cover over the entire device (to make it float), wich seemed like it would be enough protection.

So, that's what I did. But this did not work well, and in the end, it did not work at all. First, the cases are designed for wide, flat things -- cell phones. Sticking a bulky, chunky object them was not a great fit. The hard plastic top meant it was going to take a bunch of width anyway, and now it was going to take a bunch of depth, too. This made it pretty awkward in a diving pocket. In addition, the shape also put a bunch of stress on the bag in ways it wasn't designed to. Which meant it leaked pretty quickly. The PLB is designed for that, but still not optimal.

But these were not what made it a failure. What made it a failure was the time I got off a dive boat after a couple of very nice dives, leisurely put all my stuff in the car, and then checked my cell phone -- and found a half-dozen voicemail and texts from the Coast Guard! I immediately called them (but like 90 minutes or more after the messages started) to let them know that I was fine, and they told me that the helicopter was just taking off to come find me... Seems the pressure pressed the button unbeknownst to me. Huge pluses to the Coast Guard for coming to get me, and to my PLB1 getting a signal out even with the antenna stowed; but huge minuses for me to ask them to come get me when I didn't need to be.

So I haven't carried my PLB with me since then.

Until now.

Good Idea: DryFob XL

When I originally went looking for ways to protect my PLB, the only solutions I could find were either soft bags or battery pack canisters. The soft bags had the very strong advantage of cost and size; the battery canisters had the opposite disadvantages. They were very large (if you re-used an old one), or very expensive (as in $250 or more, if you had one made to a reasonable size). Which is why I went with the cell bag.

However, sometime later, @Jaan appeared with an intriguing possibility: the DryFob. This was exactly what I wanted: a small and affordable (dirt cheap, really) canister that did exactly one thing: kept its contents dry during a dive. It was very nearly perfect, except for one thing: it was too small. It was designed for keyfobs, and even the largest keyfobs are quite a bit smaller than a PLB.

But I messaged him way back in May, 2021 and mentioned PLB's, and how there were quite a few of us that had them and needed a way to take them on a dive. Of course, there aren't as many PLB's as keyfobs... but could there be enough that it would be worth a larger model?

Fast forward a year, and today we have it: the DryFob XL. It's exactly what I described: a small canister with one job: keep its contents dry during a dive. No extra holes or purposes (like either a cell phone bag or light canister), just a dry "box", but this time sized for a PLB! Yes, please.

So I purchased one (actually, two, to get free shipping). I received it a couple weeks ago, and I've had it on a few dives now, so now I can write up a review.

Continued in the next post


Continued from previous post

DryFob XL Review Information

The DryFob XL is basically just a sealed cylinder with a screw-on lid. A Mason jar of the sea, if you will. :) And like a Mason jar, it has one job: keep its contents safe and protected. It seems to do that admirably. And also like a Mason jar, it does this for a *very* reasonable price.

See the website for basic pictures: https://dryfob.com/product/dryfob-xl-waterproof-plb-container/

Overall Design

There's not much to describe about the item itself. The canister itself is made from anodized aluminum. It feels surprisingly light in the hand: you expect it to be heavier. The colors (blue and red, I got one of each) are attractive. There is a knurled texture to both the canister and the lid which makes it easy to grip. It uses two radial-sealed o-rings along the shaft to seal the canister lid, which is a pretty standard arrangement for dive lights and such. It also comes with replacement o-rings *and* a rather large tube of silocone lube in the box as well.

Opening and closing the cansister offers a certain level of resistance. I'm not an o-ring engineer, so I can't comment on clearances and tolerances; I will say that it feels comparable to my dive lights that use a similar radial o-ring sealing mechanism. It also may explain why there is a fair amount of lubricant on the pre-installed o-rings -- more than I would personally put. I found that if I sealed the lid firmly, it could be a little more difficult to get open after a dive, so I leave it unscrewed about 1/8 of a turn to avoid this. (The seal is made by the o-ring and *not* by the lid being cinched down, so this will not change its performance.)

For me, none of this is any kind of an issue, not least because this is not a canister I will open frequently. It will hold my PLB and that's about it: I won't use it for a keyfob as well, so I don't need to get things in and out. (I prefer to use a valet key: Car key storage during shore dive? ). If you *do* want to put a keyfob in there as well (and there's *plenty* of room -- more on that later), this is something to consider if you have hand-strength issues. Plus, as with any o-ring sealed device, you will want to be real careful to keep those o-rings very clean.

Size and Shape

Once we move beyond the basic design, there is one aspect of the DryFob XL that is immediately noticeable: the overall size. This thing is somewhat large -- larger than I wanted. Most newer PLB's like mine are all within a fairly comparable size: less than 2 inches by less than 1.5 inches by less than 3 inches. However, some of the older PLB's are larger. Understandably, the designers wanted to be able to allow as many PLB designs as possible to fit, so they made as big a canister as they thought they could get away with. Well, for those of us with smaller PLB's, that means that the canister is unnecessarily big. For example, I can fit my PLB while wearing its neoprene case with diameter to spare -- and more than an inch of extra internal length. In fact, the DryFob XL is a larger diameter than the battery canister for my rather large canister dive light (Dive Rite HP50), though it's much shorter in length. It's definitely something you're going to have to give some thought to, especially when you consider where you will be able to put it or how you might attach it.


Storage/Attachment Options

A very brief bit of information about me as a diver: I am a techincal diver who prefers shipwreck penetration and cave diving. This means that I dive a backplate and wing without any kind of pockets and minimal D-rings, and I try to keep my configuration as streamlined as I can. I do have pockets on my drysuit or 'tech shorts' (with pockets) for my wetsuit, but those pockets already have a lot that needs to go in them. Sticking this cansiter in a pocket will take up a lot of space I don't really have. And while I do have D-rings that I could clip something like this to, those D-rings also have a bunch of stuff on them already that I need to be able to get to, and having something bulky hanging off of them would likely interfere. Recreational divers may be able to make a different and much simpler choice: you may have a spare pocket on your BCD or a D-ring that would accept this canister without an issue. But I don't. So now what?

The DryFob XL has a few holes that you can take advantage of. There are two oblong holes on the lid. You can get a normal 1/8 or maybe 3/16 piece of bungee there no problem, or cave line, or a split ring, or whatever. You could then attach a bolt snap, or caribeaner or plastic clip or whatever, and then snap it off to whatever dangly bit you have. I think those are very useful.

There is also a hole on the bottom lip. This hole is... rather small. I don't think you could get 1/8 bungee in there, though cave line or wire or a small split ring would work. Honestly, I'm not sure this hole has a great purpose, given the much nicer holes in the top. But if you wanted to be able to tie this off fore and aft, you could make it work.

I think there's a much better way to attach this canister: just like you would a light canister. And my favorite way is the way that my Dive Rite HP50 canister is attached: with a hose clamp, a bit of strap and a bungee. See the photo: use a hose clamp at the top of the canister to hold a bit of strap that is attached to a ring of bungee to go around the bottom of the canister. This allows you to attach the canister to the webbing of a BP/W wherever you want, and do so without having to thread anything: just use the bungee to put it on or take it off.

In my case, I've decided to put it on my waist strap on my right side, right up against the plate. It's the most out of the way place I can put it, without it getting in my way. I may play with some other locations if I need to, but this is the only place I've put it so far. That will require me to put my light canister in front of it.


Continued in the next post


Continued from previous post

DryFob XL in Use​

For the first few dives I've done with it, I did not use my light canister, so I only had the DryFob XL and a pair of scissors on my right waist strap. This worked out just fine. About the only thing I can say is that I didn't notice it, which is how it should be! I was actually a bit worried about this: according to the doc, the canister is 12 ounces positive when empty. Technically, mine is not empty, but my PLB1 ain't exactly heavy -- after all, it floats... But it did not seem to throw off my buoyancy. I'd love to say that my buoyancy is so perfect that I'd be able to notice a 12 ounce change in buoyancy... but I can't. (Of course, diving even normal-sized doubles means that my buoyancy has to change by about 15 pounds on a dive anyway... :) ).


So, with a couple of successful dives without my light canister, what happened when I did have it? That happened this past weekend: I was on a boat charter to dive a shipwreck, and I would need my canister -- and, of course, boat charters are exactly where you most want that PLB!

My concern was that the DryFob XL would push my light canister too far forward. You want the light canister slightly behind your midline, and there's only so much space back there. How would it all fit?

The answer is that it was not ideal, but it was not bad, either. I put the Dryfob XL at the back against the plate, the light canister second, and my scissors the most forward. Ideally, I would have liked the light one inch farther back than it was, but it wasn't so far forward that I felt it made me wider than I needed to be. In the water, I didn't give any of it a moment's thought, which is again about the best thing you can say about something not designed to be used in the water.

Out of the water, though, the canister was a little more noticeable. Actually, it wasn't the DryFob that was noticeable: it was my light canister. Both times I geared up my light canister was twisted upside down. I think this was because the light canister was farther forward, and therefore had more room to twist around. Of course, two is not exactly a lot of times to test this out, and it's not like the canister wouldn't twist upside down on occasion when I did not have the DryFob. It wasn't that big of a deal, but I did need help from the crew to fix it. It may be something that I can adjust to when gearing up, or it may be something that makes me move the DryFob somewhere else (maybe on my left side? Maybe on my crotch strap?). But even if I leave it where it is, once the light canister is put where it belongs it doesn't really change anything during a dive, which is the important part.

Final Thoughts

For PLB users, the DryFob XL is an essential accessory. It is the only way I know of to securely carry a PLB on a dive for under $100. Cheaper soft solutions risk inadvertent activation, and more compact rigid solutions are dramatically more expensive. The DryFob XL is in the sweet spot of most function and lowest cost. It has the few features you really need: big enough for a PLB, won't allow it to be activated, water resistant to at least 100 meters (and likely much more, though untested) and enough ways to be able to mount and store the canister securely. It also has extra o-rings and lube, which is nice if you plan on opening and closing the canister frequently. It's light and seems plenty rugged. And in the water, it's been completely unnoticeable.

That doesn't mean it's perfect. In my opinion, it's larger than I want. I really wish it were half an inch narrower and an inch or so shorter: just big enough for my PLB. That would make it easier to find a place for it. But if your PLB is a bit larger than mine, I guess *you* will be just fine with the size... :) But when you factor in the price compared to a custom canister of the correct size (easily two or three times the cost) it's pretty easy to accept the size.

So if you are a diver and have (or want) a PLB, get a DryFob XL. It's the missing link to keep you safe while you're in the water, not just on the boat.

End of Multipart post

How easy was it to open on the surface after a dive?

One of my concerns is getting PLB housings open in the water without dropping parts — especially the PLB itself. It would be bad enough to loose the PLB housing's lid but dropping the PLB would be a major bummer as you drift out into open sea. When something goes bad at sea, it rarely is limited to only one problem.
To address @tridacna and @Akimbo both:

At no point have I ever thought it was too difficult to open the canister. At all times, though, I did think that it required a good grip and decent pressure to get it open. If you’ve ever used screw-on dive lights, you know what I’m talking about. They are not pickle jar hard, but they’re not easy, either.

I found that after a dive, if I had put the lid on snugly, the lid was slightly more difficult to open. Again, not pickle jar hard, but more difficult than it had been. If I screw it down snugly and then back it off 1/8 of a turn, that problem goes away, and we’re back to the screw on dive light level of stiff.

Now, keep in mind that this is coming from the perspective of an able-bodied large-handed male with no grip limitations. if you consistently have a difficult time opening jars, I would definitely try it out before I bought it.

As for worrying about losing the canister or the PLB when it came time to deploy it: that is kind of a solved problem. The sealed canister itself is slightly positively buoyant even with the PLB. And the PLB1 itself, while wearing its included neoprene sleeve, is also positively buoyant — that’s why they give you the sleeve. (ETA: The sleeve can remain attached to the device, even when you go to operate it. I’m sure it’s removable for the majority of people who are using it hiking, and don’t need the buoyancy.)

It’s possible that you might lose the canister during the dive, but I’ve never lost my dive canister which uses a very similar attachment mechanism. It might be possible that if you flooded the container with the PLB still in it that the entire contraption might be negative enough to go away, but aluminum is not *that* negative in water: if you’ve ever dropped an aluminum spool, you know what I mean. You usually have time to grab it before it disappears.

ETA: Thinking that through, I think, given the way I have mounted it, the right solution is to put the bungee ring around my wrist before I open it. That way, it is positive until I’ve opened it, the PLB is positive after I take it out of the canister, and for the briefest moment where it’s open before I take it out, it’s bungeed to my wrist. Thanks for the motivation: I think that was a valuable exercise. :)

I’m certainly not going to guarantee that there aren’t circumstances under which you could lose it, but there aren’t a whole lot of other alternatives, so if your choices are a canister that will make sure it’s there and usable 99+% of the time, or not have a solution that allows you to take it on a dive in the first place, I know which one I would choose.

ETA: As for losing parts of the canister if I were trying to deploy it in an emergency situation: I wouldn't care. Some people I understand have commented that they’re worried that they would lose the lid in an emergency situation. I would probably try not to, just out of general principle, but in an emergency situation all I want is the PLB, And I would gladly drop the lid in order to have a free hand to get the PLB out if I thought I needed to. If I lose part or all of the canister, I will laugh hysterically when I buy its replacement. I think the first one will have done its job admirably under the conditions. :)

I think people might be more worried about that if they are using the canister frequently before or after a dive, such as if they are using it for car keys or a wallet or whatever. I can easily see misplacing the lid under those conditions. But for my needs, I will rarely have the thing open. And in addition, there are holes in the lids that would allow you very easily to attach a bungee to the hole on the bottom of the canister so that the lid could never be far away.
One of my concerns is getting PLB housings open in the water without dropping parts — especially the PLB itself. It would be bad enough to loose the PLB housing's lid but dropping the PLB would be a major bummer as you drift out into open sea. When something goes bad at sea, it rarely is limited to only one problem.
Epoxy or use one of those 3M stick on rings to the bottom of the lid. Tie a bungie with a double ender bolt snap to the ring. Hook bolt snap to the plb and you now can't drop it easily. Once out and under control hook the plb to a shoulder D-ring and it won't leave you until you get in a boat or a box. Easy solutions for a life saver.
I think a valve to release pressure would be useful on these screw-on containers. I have the Light Monkey canister for my EPIRB. Unclips for access. Can’t lose parts or the device - all are connected. Much more expensive though.
I'm pondering if you could glue/bond a leash inside it to attach things to it like we do with our pockets..

Okay, someone was typing as I was thinking...
I'm pondering if you could glue/bond a leash inside it to attach things to it like we do with our pockets..

Okay, someone was typing as I was thinking...

Yes, there are 1 million ways of solving the “I don’t want to lose the cap” problem, Including using bungee on the holes that are already provided. For me personally, in an emergency, losing the cap is so beyond my area of concern. It did its job, and I no longer have a need for it at that point. :)

And everybody, don’t lose sight of the fact that this costs $100. Perfect is the enemy of good enough. And this is way past good enough.

As for pressure relief valve: those are relevant when a sealed case goes on an airplane: the air can get sucked out of the case (which is the opposite of the way the case is designed to protect) and the lid vacuumed on. In this case, we are not going to be exposing it to a vacuum, and even so any extra pressure you get inside will be from water. First of all, there should be zero. Second of all, water doesn’t expand, so it’s not going to create a large pressure. That’s why we do Hydrostatic tests, and not pneumo-static tests. :) You closed it in one atmosphere, you’ll open it in one atmosphere. I don’t want any extra holes that are possible to fail.

And again: $100. :)

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