PLBs Can Save Your Life

[letterboy]

I read some of the FAQs on PLBs and EPIRBs. Why is that the manufacturer has to change the battery? They claim that they will test it to make sure the life is 5 years. Also claimed that the cost of the battery may be more than the unit.

Something is not right.

Same reason dive computer manufacturers want you to send it to them for a battery change?

 

[Dan]

I read some of the FAQs on PLBs and EPIRBs. Why is that the manufacturer has to change the battery? They claim that they will test it to make sure the life is 5 years. Also claimed that the cost of the battery may be more than the unit.

Something is not right.

Battery will discharge with time. You need to test your PLB at least once a year. That'll shorten the battery capacity further. You don't want to have still enough charge to transmit the emergency alert when you need it. It would be bad deal when you are lost at sea, pressing the red button and finding out that it only last for say 2 hours.

 

[Dan]

I found these videos are educational and informative:

 

[JohnnyC]

Just to clear up some PLB air.

LEOSAR is just one network of satellites within the COSPAS-SARSAT network. It uses some clever Doppler wizardry that allows it to triangulate the position of a distress beacon. This is possible because the satellites whiz around. However is also means the coverage area changes.

GEOSAR is the next set of system architecture. These satellites are in geosynchronous orbit. While this means the coverage area does not change, it also means that it cannot triangulate the position of the distress beacon, and is only capable of relaying the information transmitted by the beacon. Practically speaking it means that the beacon must include positional data within its transmission.

MEOSAR is the latest generation of system architecture. It’s sort of a best-of-both-worlds operation and should allow both triangulation as well as increased coverage. This satellite array is still being built, and will continue to expand in the future.

Delays are almost always due to the response chain from the MCC to the proper authorities. With a PLB, the satellite reception of the distress beacon, outside of some exceptional situations, near instantaneous. The response to that signal is what takes time.

While a PAB may be a near instantaneous response, it is entirely dependent on a receiver actually receiving the transmission, and having the hardware to decode the data.

A VHF radio also has this near instantaneous response ability, but again, is dependent on having a receiver of the signal that can act on the signal.

Ultimately, if you can carry all three, it would be beneficial to do so.

 

[DandyDon]

I don't want to sound like I'm peddling a product here, but CustomDivers sells a delrin canister that fits just about all of the PLB's on the market for ~$100. Given the little demand in the rec scuba market, I'd say our needs can be easily met for a few hundred dollars as I illustrated up thread.

ACR making a PLB for depth would probably add a $100+ to the cost and then they have to inventory them with what would likely be abysmal sales.

I may be going to the wrong site? Is this it? PLB DIVE CANISTER NOV2016 INC BELT MOUNT

It says it's made from PVC, which might be fine, but it's not Dupont Delrin, aka Polyoxymethylene (POM) as used to make Bic lighters.

Suffice it to say that rumor has it that 34 mile range is to an antenna on a cliff while the range with diver in the water and a boat antenna only a few meters above the water is probably 10-15 miles.

I've read a couple of reviews of the device but no actual operational test.

No tests available. I think I'd want to test if it'd even reach a boat 10 miles away.

I read some of the FAQs on PLBs and EPIRBs. Why is that the manufacturer has to change the battery? They claim that they will test it to make sure the life is 5 years. Also claimed that the cost of the battery may be more than the unit.

Something is not right.

There are batteries sold on ebay that claim they can be used in ACR 2880 & 2881 for as little as $39. The page includes many warnings.

I'm having mine done by a company who claims to know what they are doing for $116. "Battery replacement service for PLBs includes a full physical integrity check, pressure test, data transmission test, replacement of seal and o-rings, installation of the new battery, and disposal of the old battery." Sounds good anyway.

This is similar to what I’ll be looking at getting for a canister. This one is 7.25” internal height and 3.5” overall diameter but I’m thinking closer to 3” overal diameter and 6” internal height.

For reference, the other canister is the Custom Divers canister.

The little round piece at the bottom is the lid, right? What is the black column on the right, with my red arrow added?

 

[Tug]

I’m 90% sure that’s the Custom Divers canister. My friend has both and had the LM made up so they can carry additional items.0

 

[Tug]

I read some of the FAQs on PLBs and EPIRBs. Why is that the manufacturer has to change the battery? They claim that they will test it to make sure the life is 5 years. Also claimed that the cost of the battery may be more than the unit.

Something is not right.

@seeker242 can probably give you the details better than most people here on the specs and what exactly is done during the battery replacement service

 

[CuzzA]

I may be going to the wrong site? Is this it? PLB DIVE CANISTER NOV2016 INC BELT MOUNT

It says it's made from PVC, which might be fine, but it's not Dupont Delrin, aka Polyoxymethylene (POM) as used to make Bic lighters.

Thanks for clarifying. I bought mine years ago from the now out of business US distributor who just so happened to be a few miles from my house and I was told it was Delrin, maybe they made a change to PVC, maybe it was always PVC. I'd still buy it today even if it's PVC. Other than a custom one off which is bit pricey, the grenade style is way too bulky and aluminum is not a good material to use for this application, all my opinion of course.

 

[CuzzA]

To add some more info, when you register your PLB you have a login that you can update. So, for example lets say you live in Florida and dive off your boat to your usual spots. You could input that info. Boat name, make, model, typical areas, etc. Hell you could even note a float plan for each trip. Something the USCG recommends every boater do. And lets say you go to Cozumel or the Indo pacific a couple times a year for vacation. You can update that info for each trip.

So, if you generally dive in Florida, but activate your PLB in Cozumel, and they check your file data and find that you updated your file to include those dates in Cozumel, well, odds are they are going to get on it.

Information is key. The more SAR teams have, the greater the odds of a successful mission.

 

[seeker242]

I read some of the FAQs on PLBs and EPIRBs. Why is that the manufacturer has to change the battery? They claim that they will test it to make sure the life is 5 years. Also claimed that the cost of the battery may be more than the unit.

Something is not right.

The battery is not more than the unit but is often the most expensive part of the unit, especially for EPIRBs. When it receives FCC approval, with a non-user replaceable battery, allowing a user to replace the battery essentially voids that approval.

There are also special tools needed. Most importantly, torque wrench, pressure tester, with the correct screw bits and electronic tester/programmer. Torque wrench is for torquing screws obviously. Each unit has a specific torque setting for the screws. The pressure tester pumps up the inside of the unit to make sure the gaskets are fully sealed and makes sure there are no cracks in the housing, so it can hold up under pressure under water. The electronic tester receives the self test signal and prints out a pass/fail report for the signal, which also shows the programming. The electronic tester is also used to reset the self test counter. Each unit will only allow a certain number of self tests. After that number, it will auto disable that self test function to save battery for a real emergency.

ACR and Ocean Signal do have a couple EPIRBs with a user replaceable battery.