PLB Recommendations/Experiences

[Wotname]

Originally Posted by s/v Jedi

The USA is the only developed country that does not have their DSC network fully operational yet. In Europe it has been fully operational for over a decade and I assume the same for AU.

I would not use a DSC sart. I would prefer an AIS sart or a 2-way device like the DeLorme InReach. The PLB is for replacing the EPIRB and to take ashore, dinghy expeditions etc.

No official DSC in Oz; some private coast stations have limited DSC or so I'm told.

Originally Posted by transmitterdan

I don't think the PLB is a replacement for the EPIRB. At least not yet. A PLB in addition to an EPIRB is a good belt and suspenders approach. The PLB is good as a backup and for when you are away from the boat.

....

What are your reasons? I know there are differences between the two but I'm not convinced the EPRIB is that much better than a PLB.
I concur with the belts & braces etc - which is what I have ; EPRIB for vessel, PLBs for crew

Originally Posted by Nicholson58

Is anyone marketing a PLB with user serviceable battery? Seems every time I get interested it turns into just another donybrook like my EPIRB that has to get mailed to a service place while we wait for it to be returned - maybe.

I'd like to see one that resides on my batteries with an automated and/or manual self check including a battery load test. It should be able to tell you if it fails to operate and when the battery is junk and it is not rocket science to replace one. We (all of us) are sharp enough to navigate the entire planet, manage a complex vessel, engines, generators etc but are somehow to dumb to change a battery. (or stuff a rubber boat in a box).

GME (in Oz) have a simple battery plan. Send PLB back after 7 years and they send you a new unit for half price; or so it was last time I checked - say 2 years back.

[transmitterdan]

Originally Posted by Wotname

No official DSC in Oz; some private coast stations have limited DSC or so I'm told.

A good feature of DSC is it doesn't depend on any official stations. A DSC distress call will alert on all other radios in the vicinity. And you can talk to them. An EPIRB or PLB can't do that as they are one-way only radios.

Originally Posted by Wotname

What are your reasons? I know there are differences between the two but I'm not convinced the EPRIB is that much better than a PLB.

An EPIRB seems to be a more rugged piece of gear. It will transmit for typically twice as long as a PLB and it has somewhat more power output than a PLB. The EPIRB antenna is better in my view and more likely to be heard than a PLB.

A PLB is a good backup to an EPIRB. My personal theory is that if an EPIRB went off and then a few hours later a PLB went off at the exact same location the authorities would have little choice but to recognize it as a real alert. I'm not saying they won't respond to a PLB issued alert but I just feel more comfortable relying on the more rugged EPIRB. If nothing happened within 24 hours (less if in real danger) we would set off a PLB. If more than one PLB is available we would set off another one every 24 hours until something happened.

Priced at $250 PLBs are basically throw away devices in my opinion. I don't think there is much point in fretting about battery replacement. If it lasts 5 years by then there will be something a lot better/smaller available anyway.

On the other hand having the factory or tech center replace an EPIRB battery is a good idea. They do a lot more than just replace the battery. They make sure the device outputs full power, has the right frequency and otherwise works as good as when new. These are checks that a typical user can't do themselves. So at an ownership cost of less than $100 per year an EPIRB with 10-15 year life makes it a reasonable investment.

[CarlF]

After careful comparison, I choose to carry two PLB's instead of an EPIRB for roughly the same cost. Same transmit power (5w). Same beacon database. Both PLB's have a GPS. Batteries have the same lifespan (5-6yrs but much longer in real life). The difference between 24 and 48 hour transmit life is of no importance to me as GPS location fix is transmitted in less than 10 minutes and drift can be charted in less than an hour.

The obvious benefit of the two PLB's is redundancy. Complex electronic devices do not always work.

[Dockhead]

Originally Posted by transmitterdan

I don't think the PLB is a replacement for the EPIRB. At least not yet. A PLB in addition to an EPIRB is a good belt and suspenders approach. The PLB is good as a backup and for when you are away from the boat.

I don't get the point of the AIS SART except that it is smaller than a DSC handheld. Granted smaller size is nice but a DSC handheld can handle the MOB function and a lot more. Except for size, which to me isn't such a big deal, why would someone rather have AIS SART than a DSC handheld radio?

Why don't you think that a PLB is a replacement for an EPIRB? It performs exactly the same function, except in a different form factor and with somewhat less battery life. In my opinion, a PLB (and even better, two PLBs) is an excellent substitute for an EPIRB, as it does basically everything an EPIRB does, plus it can be kept on your person, meaning there is much less risk you will abandon into the liferaft and leave it behind, and it might save you in the dinghy or in a MOB situation.

As to DSC handhelds - the form factor is the whole problem. Present DSC handhelds are too bulky to keep on your person at all times. You can't keep one in your liferaft pocket. Plus you have to keep them charged. A DSC handheld, to be useful for this purpose, would need to be much more compact (let it be non-floating, but with a sturdy lanyard). And it would need single-use batteries (like AA lithiums) so that it's always ready. I would be the first to buy such a device. You don't necessarily need fully built out DSC system on shore, pace Dave - boats and ships around will receive your signal, and plus you can communicate with your rescuers.

[Neptune's Gear]

I have an EPIRB for the boat, and plb's in our inflatable life jacket/harnesses. Next time offshore, I'll have one of these http://www.neptunes-gear.com/collect...n-in-the-water . I like the idea that I, or any other AIS equipped vessel in the area can find the mob. DSC is not widely a enough in use yet.

Sent from my Nexus 7 using Cruisers Sailing Forum mobile app

[Wotname]

Originally Posted by transmitterdan

......
An EPIRB seems to be a more rugged piece of gear.....
Debatable

It will transmit for typically twice as long as a PLB .....
True but not so much an issue if the PLB has an imbedded GPS.

and it has somewhat more power output than a PLB....
I have never seen a PLB with less than 5 watts - same as EPIRB - but perhaps some (older ones) do exist

The EPIRB antenna is better in my view and more likely to be heard than a PLB....
Perhaps; the EPIRB antenna is designed for the unit to be floating in water while a PLB antenna is designed for the unit in a pocket or similar. I have not seen any critical analysis of the efficiency of either antenna but my gut feeling is that the EPIRB may be slightly better.


A PLB is a good backup to an EPIRB. My personal theory is that if an EPIRB went off and then a few hours later a PLB went off at the exact same location the authorities would have little choice but to recognize it as a real alert. I'm not saying they won't respond to a PLB issued alert but I just feel more comfortable relying on the more rugged EPIRB. If nothing happened within 24 hours (less if in real danger) we would set off a PLB. If more than one PLB is available we would set off another one every 24 hours until something happened.

Priced at $250 PLBs are basically throw away devices in my opinion. I don't think there is much point in fretting about battery replacement. If it lasts 5 years by then there will be something a lot better/smaller available anyway.

On the other hand having the factory or tech center replace an EPIRB battery is a good idea. They do a lot more than just replace the battery. They make sure the device outputs full power, has the right frequency and otherwise works as good as when new. These are checks that a typical user can't do themselves. So at an ownership cost of less than $100 per year an EPIRB with 10-15 year life makes it a reasonable investment.

[transmitterdan]

Do we need to have a thread about DSC? It seems there are misconceptions about it. For 10 years at least almost every fixed radio sold has had it and reception is turned on right out of the box. It is almost ubiquitous I would think. There is no government infrastructure required and 99% of radios do not have the DSC alert turned off. I think it's more likely that you would get a response from a DSC alert than AIS. Is this assumption wrong?

[s/v Jedi]

The 24-hour battery run time of a PLB is for cold climates. In warm climates, the run time is longer.

The rest, there is no difference. Output power, GPS receiver, antenna gain etc. are all the same. Also, my McMurdo Fastfind220 is at least as robust as my previous Epirb.

Everything gets smaller; smaller doesn't mean lesser. McMurdo also sells a PLB with 48-hour battery run time; it's bigger, to accomodate a bigger battery. I don't feel it makes sense unless sailing in cold areas, maybe. Instead of two PLB's, we carry one plus a 2-way InReach. Allows you to communicate with rescue, tell them to hurry, that you really need help, ask how much longer etc.

If I had two or more epirb/plb's, then I would a tivate them all at the same time instead of one a day. If the number of signals is what makes them move, I'd rather have them move on day one already.

[Dockhead]

Originally Posted by transmitterdan

Do we need to have a thread about DSC? It seems there are misconceptions about it. For 10 years at least almost every fixed radio sold has had it and reception is turned on right out of the box. It is almost ubiquitous I would think. There is no government infrastructure required and 99% of radios do not have the DSC alert turned off. I think it's more likely that you would get a response from a DSC alert than AIS. Is this assumption wrong?

I completely agree, but AIS has one really big advantage -- you get a continuous, real-time position report, which could be invaluable for locating a casualty. A DSC distress message only gives one position report -- after that, you have to manually do position polling, and that's IF the device is capable of responding to a position request.

So little different purposes -- DSC is much more effective for sending out the alarm, for the reasons you state; but AIS is needed for guiding you to the casualty. Since both could use the same radio and antenna, it would be really good to have a SART beacon combining both functions.

Oh, and please! Two-way voice comms on 16 and 9 would round out the perfect MOB device.

[S/V Alchemy]

Originally Posted by Dockhead

Are you sure its a ResQLink? I thought those were introduced only in 2011 or so, and that they are still the most compact PLB available?

Well, I checked, and you're right, my terminology was incorrect. It's this model:


The "ResQfix". It's got the 406 Mhz GPS transmitter, which is the important part, I think. Newer models are less bulky but do essentially the same thing, so I will hold off getting something newer until we push off.

[Neptune's Gear]

In my experience DSC is virtually useless in many parts of the world. Here in NZ, for example, it is virtually unused. Yes, many VHF sets have it. Most are not programmed with MMSI, or connected to a GPS. AIS is REQUIRED by the commercial boats, and is spreading through the pleasure boat market, esp the offshore yachts. There are shore stations as well. IMO, I would far rather rely on a AIS SART than a DSC SART. Anyone who can hear or see the signal (on a plotter) can come directly to you. Again, IMO it is more use in more places than DSC.

[transmitterdan]

Originally Posted by Neptune's Gear

. Yes, many VHF sets have it. Most are not programmed with MMSI, or connected to a GPS. AIS is REQUIRED by the commercial boats, and is spreading through the pleasure boat market, esp the offshore yachts. There are shore stations as well. IMO, I would far rather rely on a AIS SART than a DSC SART. Anyone who can hear or see the signal (on a plotter) can come directly to you. Again, IMO it is more use in more places than DSC.

MMSI programming is not required to receive DSC alerts. MMSI programming is only required to send position or for ship to ship calling. A radio with no MMSI programmed or GPS connected should go off if an all ships alert is heard. Only the person sending the DSC alert needs these things.

AIS won't work without MMSI and GPS antenna. DSC is no more work that AIS and less in many ways.

I would guess there are 10 times more DSC receivers that AIS in most locations. Nearly every fixed mount VHF sold in last decade has it. Most users don't know it's even there. But when turned on the radio is always listening for an all ships alert.

[Wotname]

Originally Posted by Neptune's Gear

In my experience DSC is virtually useless in many parts of the world. Here in NZ, for example, it is virtually unused. Yes, many VHF sets have it. Most are not programmed with MMSI, or connected to a GPS. AIS is REQUIRED by the commercial boats, and is spreading through the pleasure boat market, esp the offshore yachts. There are shore stations as well. IMO, I would far rather rely on a AIS SART than a DSC SART. Anyone who can hear or see the signal (on a plotter) can come directly to you. Again, IMO it is more use in more places than DSC.

Similar situation in Oz.
Additionally you have to be in VHF range for DSC to be useful.
I'm far more likely to be out of VHF range of other vessels and shore stations when the stuff hits the fan and would much rather rely to COSPAS SARSAT system.
YMMV.

[transmitterdan]

Originally Posted by Wotname

Additionally you have to be in VHF range for DSC to be useful.

Same is true for AIS. They use the same technology so have similar range and the need for other receivers in range.

No one is saying that DSC and/or AIS is a substitute for EPIRB. They are completely different. But if you fall overboard with a PLB or EPIRB your own ship is going to have a tough time finding you. With DSC (or AIS SART) they can easily find you. And the MOB does not have to be conscious for DSC to work. The mother ship can request position of your handheld and it will reply for you and the MOB location can even be displayed on the plotter just like AIS. And the MOB can send a distress call with DSC if the crew doesn't know they are gone. A loud alarm will go off on the VHF and your coordinates will be transmitted. Any DSC radio in range will hear it. No special AIS gear is required. Basically this is what an AIS SART does except it does not allow the ability to speak to the MOB like DSC. The AIS SART does keep sending MOB location without user intervention but with DSC the mother ship has to keep asking for your position.

We definitely need a DSC/AIS thread started by an expert. It seems many don't understand what DSC and AIS can and cannot do.

One really neat feature of DSC if you are out on a dingy and have "lost your way after drinking...err...darkness" you can ask the mother ship to send it's coordinates. Then the DSC handheld can set that as a waypoint and you can find the boat. DSC has many uses even if no other boat for miles has it.

[goboatingnow]

Originally Posted by Wotname

Similar situation in Oz.
Additionally you have to be in VHF range for DSC to be useful.
I'm far more likely to be out of VHF range of other vessels and shore stations when the stuff hits the fan and would much rather rely to COSPAS SARSAT system.
YMMV.

Given that as a MOB device one would assume you have a equipped receiver either AIS or DSC. then as mob warning devices these ate far superior to plbs.

Dave