Scuba diver's Personal Locator Beacon - how never to be lost at sea

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Mike

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I'm putting this thread here in the Cozumel forum because this is where I got the inspiration to finally pursue something that I've been wanting for years, which is a fool proof, absolute guarantee against ever getting lost at sea when diving. The Scuba Mau boat sinking in the channel between Cozumel and the mainland in February 2012 really got me thinking what device would I have wanted with me if I was ever in that situation, I pictured my wife and myself like them floating for 5 hours in that water or even in a worse situation, totally washed out to sea, no land in sight. I started getting more motivated. The unfortunate dive accident in Cozumel of Cristina Cassin in March 2012 and her disappearance really got me thinking. I started thinking of being separated from my dive buddy who is my wife and her floating alone at sea and how helpless I would feel and how horrible I would feel if I knew that I could have done something to have given her a rescue device. Finally I got more serious and with Thanks to Ron Lee and CVChief for things they've posted and questions they've asked that helped lead me to this final solution, here it is and the odyssey I'm currently going through to make this happen.

I've known about EPIRBs for a long time which are devices that send a signal to a satellite to give your GPS location to help search and rescue find you, however the problem with them has always been that they aren't designed to go to depth, so they wouldn't work for a diver, that is if the diver wanted a device actually on his person at all times. Also EPIRBS are large in size. Looking into EPIRBs led to looking at PLBs, (Personal Locator Beacon) the little brothers to EPIRBs and much smaller. They have come a long way over the years, PLBs have grown from something a hiker might take with him to now a full blown mini EPIRB. More research lead to a specific PLB made by Ace Electronics, on July 2011 they came out with what is known as the smallest PLB on the market - the ResQLink. Shortl after they released the ResQLink+ which floats and has additional external plastic loops for strapping to a life vest or in a diver’s case a BCD. Now it seemed we were on to something. I’ve found the world’s smallest PLB, floats, waterproof... this was starting to look promising. However I soon realized, waterproof doesn't mean diveable. We still have the issue of even the ResQLink isn't able to be dived with; it's only water proof to about 16 feet. Stuck again.

Along comes Ron Lee sometime in March of 2012 and he posts a link to a company called Custom Divers and their offer of a Fast Find PLB and a 200/210 dive canister. I'm excited and back on the trail, here looks like a solution- a 'dive canister', I've never heard of it, but apparently these are water proof to depth. Unfortunately, I soon discover Custom Divers is located in the UK; I spent time on their website and could find no way of getting them to ship to the US. I emailed them asking if they could ship to the US but never got a response. A week later I get motivated to start researching dive canisters online. If there is one, I figure maybe there are many and somebody in the US surely offers them. This led me to McMurdo. Seems they make some serious at sea rescue devices and have a dive canister and you can find them matched up with the Fastfind PLB. I still want the ResQLink+; it's smaller, lighter, waterproof, it floats, and it’s less expensive than the FastFind PLB. The McMurdo canister is larger and bulkier it doesn't have any built in attachment methods like the Custom Divers 200/210 does. I’m sure the ResQLink+ is the way to go, keep it light, small and compact. I just need a smaller dive canister.

Another week goes by; I get some free time and get back on the hunt. Guess what? As of April 2012, there are exactly 2 dive canisters I can find on the market place, the McMurdo and the Custom Diver 200/210 and that is it. I'm shocked and stumped. I've got the PLB figured out, but I'm back where I started, with no way to take it diving. I spend the next week on and off researching do it yourself solutions, reading about cave divers and canisters they have made out of PVC pipe, lots of stories end with implosions at depth, lots of really bulking canisters. Seems like a dead end. About a week passes and I go on the Ace Electronics website and decide to try to contact them, maybe they have a recommendation of how to dive with their unit. I find contact information and leave a message with support telling them what I'm trying to do and ask them if they have had other people do what I'm trying to do. I leave them info about the FastFind PLB and the McMurdo canister; I even emailed them with links to it all. Unfortunately, I never hear back from Ace Electronics. Dead in the water again.

A few more days pass and I eventually go back to Custom Divers UK website to look at their canister again. I am now armed with dimensions of the ResQLink and see that darned canister over in the UK seems like it's very close in size, and sure seems like it's got possibilities of working with the ResQLink unit, however I can't figure out how to buy one. Frustrating. Finally I dig all over their website and I stumble across a small bit of wording about a US distributor. Wow, here we go! I send off an email to the email address and George Caves replies back within hours that he can sell them to me. Bingo! Next email is me sending George the how and why I want them and I give him dimensions of the ResQLink and ask him to see if he thinks it will fit in his canister. George replies back that the measurements are very close. They are so close he is worried about saying yes or no to it fitting. He does offer that if it doesn't fit, he will take the canister back if I pay for return shipping. That was good enough for me, I figure let's get a canister in hand and then figure out the rest. I mean this is half of the puzzle and I’m getting one of these!

I give George a credit card and he ships me a canister for $99.61 plus $8.20 for shipping. It shows up April 8th.

to be continued...

Canister1.jpgcanister2.jpg
 
Mike, great job. I thought a link I found in a rescue aids thread had a US contact. Maybe not. It may have been in this link:

http://www.scubaboard.com/forums/ge...ignalling-equipment-searchers-point-view.html

The McMurdo canister has a "cutout" for webbing/strap and a hole on the lid where I have a wrist strap. So it has two methods than can be used for attachment to your BC or similar.

However, the path you are taking may be far better. It looks like a smaller container and it may be a lot cheaper than my canister.

The ACR PLBs look like great units. You may be able to go to a sporting goods type store and do a fit check before buying the PLB.

I already have a Fastfind Plus that I bought about six years ago and its diving canister. If I were to get a similar system now, the route you are going is probably what I would do as well.
 
Last edited:
What is the battery life on a strobe?
 
April 10, 2012

Now I have a Custom Diver 200/210 dive canister in my possession it’s time to figure out if the newest ResQLink+ will fit (The floating version is larger) or if it’s going to be the first version the ResQLink which doesn’t float. I’m confident one of them is going to fit; it’s time to figure out which one. Using the specifications from their website I see the standard ResQLink is 3.3cm x 4.8xm x 9.9cm tall. The floating version is a bit thicker and a bit taller; it’s 4.1cm x 4.8cm x 11.4cm tall.

I start by just taking a ruler and trying to measure the inner dimensions of the dive canister. It’s obvious that width and thickness of the unit is not going to be an issue and the crux of this is going to be the height. The standard unit will fit, without a doubt, but the extra height of the ResQLink+ is going to be really tight, I can’t really tell positively anything yet. Problem I didn’t count on is the canister inside height is hard to measure and take into account how much the threads will actually reduce the heights when the unit is joined together and screwed down. We seem to be talking about just millimeters of difference here could determine whether the PLB will fit or not.

Plan B, make an actual sized 3D version of the ResQLink and just put it inside the damn canister and screw it together! That ought to be a surefire way to see if it fits or not. A quick trip to the garage yields a scrap piece of wood and within a few minutes I have a dimensionally accurate (at least in height) doppelganger. I stick it inside and screw the canister together and it fits! It fits snuggly. I shake it, no noise, can’t feel any movement. Wow, there is no room for error what-so-ever. On the positive side I’m thinking that’s a good thing, there will be no worries of the ResQLink banging around inside the canister at any time, that should be a plus, keeping it nice and snug and safe. On the other hand now, I’m looking at the picture of the ResQLink+ that I have printed out and I notice it has two plastic loops at the top and bottom of it. My suspicious mind is starting to wonder just how did they measure their unit to come up with the dimensions? Is the 11.4 cm a true measure of the unit from top of loop to bottom of loop or is that only the measure of the main case of the unit and those loops are not taken into account? If it’s the latter there is no way it will fit.

I figure I’ll try to call the manufacturer and see if I can get some answers. They are in Florida, I’m in Colorado, its 7:30am, and they should be at work. I find their technical support phone number and give them a call. A tech support person named Jack answers and I explain what I’m trying to figure out. He seems to understand the issue and he says to hold on, that he will go grab one, he has a ruler and he will find out for certain. A few seconds later he declares the 11.4 cm measurement includes the plastic loops on top and bottom. Sweet. Thanks Jack!

So I’ve got one canister, I’ve made a dummied up version of the ResQLink and gotten it to fit; I’ve contacted the company and gotten verification of how they measured it. Next step looks like it’s time to order a ResQlink+.

To be continued…
 

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Nice work Mike! I still think a better antenna system is needed for the PLBs. The freqs they operate are line of sight. If you're in even moderately heavy seas, that's a tough scenario for the radio to operate effectively, with the short stub antenna provided. In another thread I suggested having a proper length antenna that could semi-permanently be fastened to, and rolled up in a SMB. This would require an additional port for an external antenna, or a compatible connector for the existing antenna, that could be used interchangeably. Either a BNC (bayonet) or TNC (threaded) connector could work. The additional length of the antenna would boost both RX and TX capabilities a good deal, increasing the range with no other modifications. I'm not an engineer, but worked on military aircraft radios and navigation equipment for many years.
 
Tom, I do not think that PLBs need another antenna. The PLB output signal is already able to be picked up by geosynchronous orbiting satellites 19,323 nm above the equator (slant range for most users is higher).
 
Tom, I do not think that PLBs need another antenna. The PLB output signal is already able to be picked up by geosynchronous orbiting satellites 19,323 nm above the equator (slant range for most users is higher).


:bonk: I was thinking an antennae for the EPIRBS. Duh. Only seven years retired and I'm getting stoopid, I guess.
 
Mike great work. If you get one who gets to dive with it, you or the wife? I assume if it all works you will want two.
 
Tom, you can much mo stupid than me so please, don't try to win the stupid prize. A PLB is just a personal version of an EPIRB. They are similar in that they use the same frequency and probably transmission protocols.

No doubt EPIRBs have unique requirements (flotation, etc) since they are designed to be used on boats.

You do raise a good point on whether a PLB activated by a diver in the water (surface) works properly. If I can find a contact (perhaps ACR or NOAA), I will ask that question.
 
We ordered a few of the canisters from Custom Diver as well, and once we take a look and check for fitment with the ResQlink, we're adding them to our rental packages.

Also, if they look good, we'll be buying at dealer/wholesale/bulk prices, so we may be able to offer some good deals on purchases of this canister in addition to having them in the rental package.

We also have the aluminum McMurdo canister - once we have both I'll do a side by side video compare to give everyone a better idea.
 
https://www.shearwater.com/products/perdix-ai/

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