EPIRB, PLB, Tracker. What's the difference?

[erice 732]

[rigger 47]

NZ does have DSC coverage - but not for VHF or the 2MHz band
 

from http://www.linz.govt.nz/system/files_force/media/pages-attachments/nz04c.pdf

New Zealand DSC Coverage
2. The system, based at Taupo Maritime Radio, has a coverage area for the Global Maritime Distress and Safety System (GMDSS) oceanic area designations* A3 and A4 in the New Zealand monitored sea area NAVAREA XIV.
3. DSC is not used on the maritime VHF or MF frequency bands and does not cover the GMDSS in-shore area
designations* of A1 and A2.

[Beccara 25]

For the record I have no interest's at all in AIS companies, I hold no stock portfolio in any company let alone a marine one. My employers current and past aren't involved in selling AIS systems and I hold no personal contacts within any such company. I also note i have not mentioned any specific brand or unit type at all and have stayed away from talking about sat based AIS aswell.

 

My background is RF and safety networks however, I have extensive experience in sub-ghz and microwave network design and deployment for both commercial and life critical networks

 

I have no interest in getting people to spend money on anything, I do have an interest in making sure people understand safety networks and underlying safety principals. Anyone who has a genuine question around data networks and safety is welcome to contact me privately 

[wheels 543]

Rehab, the Gvt will NEVER pay for the implementation of DSC. AIS was made compulsory for Commercial shipping and commercial had to pay for it. Local Harbors had to pay for the installation of the network to relay it etc. and then many like Marlborough then made local commercial pay for that too. CG would not exist if not for Volunteers. Rescue Helicopters would not exist if not for Westpack and many others donating to it. So the Gvt funding DSC just wouldn't happen. They are pushing further and further into the world of user pays. That would be fine if it meant we had proportionally lower taxes, but well........that'll never happen either.

[Beccara 25]

To reaffirm to myself some of my comments about DSC i have chucked all of the repeater locations into our RF planning systems and run the use case on flat seas with a 1w handheld 0.5m above the water line. Tech wise that is requiring 12db of SINAD which is the min needed for DSC to come through as anything other than complete garbage

 

 

As you can see whist there is good coverage there are some fairly massive holes. You'd need to boost the number of stations 3-4x what they are today to get enough ubiquitous coverage where you'd be able to say with some confidence you could use DSC to alert the CG and they'd get it 

[rigger 47]

I keep seeing the mention of email  so when I saw in a recent post the one touch email had an * I looked it up

 

 

       One-touch e-mail access

An SSB first! The IC-M802 can be set to memorize your HF e-mail access frequency, mode and bandwidth settings.

At sea e-mail has never been easier. * Please consult with an HF e-mail provider for details.

 

 

So it is not part of the DSC system -You have to have an email provider and a modem

 

NOTE:

For e-mail operation, you MUST make a contract with an HF e-mail provider and purchase an e-mail modem from the provider or your dealer

 

Apologies for thread drift

- I spent a number of years working in areas where vhf DSC was supported - it was a complete pain in the proverbial - only one genuine distress call and the voice mayday call on VHF 16 came through first, it was not until I turned the ship around and steamed towards the vessel (~40nm away) that the VHF DSC alarmed.

When at anchor the OOW on watch or duty AB if OOW had to leave the W/H would hear any alarms that the system generated - Trust me the standard alarms are loud enough - to the point where when on location with an installation with a dedicated Radio officer - the SSB, Inmarsat C, DSC VHFs etc would be shut down to avoid disruption when doing the more riskier jobs and an entry in the radio/gmdss log would be made.

 

On the PLB / MOB device - I will be getting an AIS MOB device unit for myself shortly - not one with DSC capability as I see little value there, nor Sat capability. With what I do if I end up in the water by the time the SAR folks get notified I would either be dead or picked up (could well be dead). My focus is on not getting in the water to start with - but it could happen....

[Fish 0]

Agree with Rigger, when sailing around the Solent (UK) the number of false DSC alarms was crazy. They are like car alarms, seriously noisy, invasive and completely pointless. You'd be lucky to get one genuine alarm out of a thousand. Most people would turn the VHF off completely to not get the false alarms, doesn't matter if you were on ch 16 or not, they override everything, and can only be silenced by the sender, major pain in the arse.

[Beccara 25]

On the PLB / MOB device - I will be getting an AIS MOB device unit for myself shortly - not one with DSC capability as I see little value there, nor Sat capability. With what I do if I end up in the water by the time the SAR folks get notified I would either be dead or picked up (could well be dead). My focus is on not getting in the water to start with - but it could happen....

 

All AIS SART's are being picked up by sat these days most of the time, The 2010 trials went very well and many companies have launched birds with AIS detection as a side function, There's still some black spots globally depending on the day but it's improving and the companies involved in fleet monitoring products are passing SARTS to the COSPAS ground guys when they pick them up

[Fish 0]

Hi Rehad,

Is there any chance you could post a summary of your last post?

Its too long to read.

I don't feel I can contribute meaningfully to the thread if I haven't read the last post, and it would be a shame to let such an important topic fizzle out due to the lack of a summary of a post...

[Black Panther 1,591]

I hate you Fish  

[Fish 0]

DSC doesn't work, it makes everyone turn off their VHF's, so they can't hear voice messages either and legit voice mayday calls. the frequency of false alarms and the inability to silence them is a fundamental problem of the system.

 

That is the difference between theory and reality. Fact.

 

That is reality based on experience Rehad. My opinion only, but none the less reality based on experience in one of the worlds busiest waterways, the Solent.

 

And I don't see what is wrong with existing comms systems, two forms of communication, a phone and a VHF. Every time I've needed assistance I phone (so no one knows its me again ) if its so rough or dangerous to not be able to use a phone or VHF, you should probably be focusing on dealing with it yourself rather than this pre-occupation of someone else coming to get you out of the sh*t.

 

Failing immediate voice communications, and getting back to the original post, a GPS enabled EPIRB or PLB is more than sufficient, especially when combined with other risk mitigating factors such as good seamanship, etc.

 

This focus on gadgets and technology as a safety blanket can have an adverse effect on real safety, being personal responsibility and sound decision making.

[Beccara 25]

 

This focus on gadgets and technology as a safety blanket can have an adverse effect on real safety, being personal responsibility and sound decision making.

 

That is an interesting side effect and one of the main differences between aviation and marine safety cultures in the recreational space. In Aviation any crash commercial or recreational will create an investigation which WILL find the root cause (Even if it takes years) and as such there is a real focus on these qualities despite having all the "gadgets" as safety measures, Better to leave a body that is known as doing everything right than a body used as an example in a "human factors" case.

 

I do feel that because of the international nature of recreational boating doing a NTSB/CAA type investigation into boating accidents and incidents has been placed in the too hard basket

[Fish 0]

 Fish.

 

As that has been stated previously on this thread and other threads VHFs are not on except for schedule weather forecasts times for channel 16 then turn off by most nz boaters and we do not have VHF DSC as yet. 

 So your confirming you believe VHF's aren't normally on. That supports and verifies my argument that DSC will not work, because the VHF needs to be on for it work work.

 

Doh!

[Fish 0]

 

Your reasoning also suggests that MAY day Calls and other emergency calls are not being broadcasted /. receiving and also failing. So you are confirming the whole VHF radio service is failing or about to collapse as a communications system.

 

 

Most people are competent enough to turn their VHF on before issuing a Mayday....

 

And yes, myself and the other adults on my boat have VHF tickets and just about every other ticket known to man, ranging from day skipper to Ocean Yacht master and sea survival etc, not exactly sure what point that proves though. As I mentioned earlier, I use my phone to call Coastguard, its private, quieter and much more efficient. Everyone already has one or more phones, already know how to use them and don't need a licence to use them.

 

Do you know your vessels MMSI number and know how to programme it into a DSC VHF - its a pain in the arse, especially when you want to go on your boat for a pleasant sail, not programme the DVD to record something, or some other silly electronic technology.

 

Just take your phone. If you are going a wee way out, get the Vodafone long range service, its not complicated. Doesn't need to be complicated (like DSC)

[JK 28]

 

Your map re VHF coverage. How come I have had continuous vhf coverage from Auckland all the way to 20 miles pass north Cape

 

 

 

Maybe because you advocate sailing within a few 100m of the coast.

[Beccara 25]

Maybe because you advocate sailing within a few 100m of the coast.

 

The maps are based on DSC handheld power levels (1w) with the handheld 0.5m above the water. This is what you would see with a MOB DSC event. Alot of boat based VHF's have 1w or 25w operation and more height. I fully expect that a onboard VHF at 25w 15+ft would get much, much better coverage without any real black hole.

[Black Panther 1,591]

I always thought the Aussies went a bit silly over things like this after that nasty SH.

[rigger 47]

Apologies everyone - hit page down.

 

Rehab.

I take it

“So what's wrong with a e-mail provider there are 160. most boats I have been on have had two and SAT PHONES WITH FREE E-MAIL ACCOUNTS.”

 

 

Was aimed at me.

My understanding for email via HF is that you need a modem that works with the SSB – and a shore provider that operates the receiving HF gear. How much for the HF modem - another bit of kit.

I have heard of yahoo and gmail – but as far as I know they do not have HF stations.

Please post details for the sat phones with free email.

 

Dsc also allows you to inform any number off vessels providing you have their details.

 

 

Provided they are in range

 

During a race if DSC was common place you would have a half dozen or so boats pre programmed to receive the distress call and other vessels that usually transit / sail the same areas,

 

 

Why bother with pre programming half a dozen boats in when a DSC distress call is automatically an all ships call

 

Most take 3 - 4 miles to slow and are on auto pilot.

 

 

Ships are required to have a tactical diameter of

Did an MOB exercise on a tanker at full sea speed. Got her turned and stopped alongside the "victim" in fairly short order. Rescue boat could have been quicker but was not the point which was for the deck cadet to con the ship.

Auto Pilot – so what takes no time at all to turn it off. Do you know what a BNWAS is?

Not all ships are badly crewed.

 

 

How many stories have you read where a life raft person has fired 2 or 3 parachute fares, and smoke flares  only to watch the vessel to sail over the horizon.

 

 

Have you heard of the number of people rescued by ships passing by or ships diverted from 100s of miles away, or the yachts that commercial ship protected from pirates.

Did you know that all SOLAS vessels >300GT are required to have a Class A AIS unit onboard and operating, and they alarm when an AIS SART /  PLB is detected.

 

AIS has not been operating long enough to prove it's worth or for faults / failers to happen..

 

 

AIS has been a requirement for all ships >300GT for about 11years (implementation started in 2002/03) – standards are changing and there are errors(positional mostly) – BUT – from experience the officers use the AIS provided data/equipment a hell of a lot more than any of the DSC gear.

DSC (as part of GMDSS) has been required for about 16years, implementation started in the early 90s but the false alarms still happen far too often.

 

Falling overboard usually happens during gale and storm weather conditions., I would not like to be within one mile of a large coastal or oceangoing vessel during those conditions. would prefer a yacht with a throw line.

 

 

So the rescue boat that many ships carry would be useless? Large ships can make a lee for a rescue to occur.

I know of more people that have gone overboard in moderate to calm conditions than gale / storm.

 

To me AIS is of far more practical day to day use than DSC - DSC does nothing for collision avoidance. If the gear is really simple to use and provides daily practical value it will be used. Unfortunately DSC is of little practical day to day use therefore it sits in a corner and is cursed for the multitude of false alarms that distract from navigation / keeping a lookout - maybe that is why flares are not seen - a false alert from 1000nm away calls attention away...

[Fish 0]

Good post Rigger, makes me want to go and investigate this AIS a bit more.

 

I believe most MOB's occur at anchor or in the marina, generally involve alcohol, peeing and or getting into or out of a dinghy, not during rough weather.

[Fish 0]

Now Rehab, fairs fair, I answered your question in VHF tickets, now you answer my question on programming the numbers into a DSC unit. Do you know the MMSI number for your boat and how to program it into the DVD player, vhf or other appropriate electronic device that sitsin the corner?