Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 16-09-2012, 02:44   #1
Registered User

Join Date: May 2011
Location: Currently in Spain
Boat: Hanse 385
Posts: 653
EPIRB or PLB info direct to boat?

Hello all,

Say I got something like this small PLB..

Product Details - e-marineworld - Your Safe Harbour for Marine Products

Sailing with one other person. Attached it to a life jacket, etc, and fell in the drink then activated it.
Is there a way to pick up the GPS details directly on the boat so the other person still on board can pick you up?


Say you're 1000miles away from the nearest ship, would you be contacted directly via the rescue services with the current GPS feed as YOU would be the closest boat around?

How does this work?
__________________

__________________
simonpickard is offline   Reply With Quote
Old 16-09-2012, 03:30   #2
Registered User

Join Date: Jul 2012
Posts: 175
Re: EPIRB or PLB info direct to boat?

as I understand it, the only way to get the MOB's position is via the search and rescue centre in the country of registration of the PLB. If the person left on the boat has a sat phone (Iridium) they can call up the search and rescue centre and get the position.

Others may have other information.

BTW, thats a very good price on the PLB, nice to see they are still coming down in price. I paid $580AUD for a GME equivalent 2 years ago.

Lee
__________________

__________________
banjoship is online now   Reply With Quote
Old 16-09-2012, 03:38   #3
Registered User

Join Date: May 2011
Location: Currently in Spain
Boat: Hanse 385
Posts: 653
Re: EPIRB or PLB info direct to boat?

Shame if there isn't a way to get the location. Seems to me in the vast majority of cases the boat the poor person has fallen off would be the closest.

Would be great if there was some way to get that info to the boat straight away.
__________________
simonpickard is offline   Reply With Quote
Old 16-09-2012, 03:44   #4
Registered User

Join Date: Feb 2012
Location: Denmark
Boat: Crewing on a Nauticat 33
Posts: 95
Re: EPIRB or PLB info direct to boat?

There is the possibility of supplementing with an AIS beacon on each vest. That would pop up on your mapplotter if you had an AIS receiver on board. An example would be PERSONAL AIS BEACON . I wonder if there are any combined devices so you don't have to carry around multiple gadget on your vest?
__________________
madsb is offline   Reply With Quote
Old 16-09-2012, 05:01   #5
Registered User

Join Date: May 2011
Location: Currently in Spain
Boat: Hanse 385
Posts: 653
Re: EPIRB or PLB info direct to boat?

That's exactly why I'm asking. I just want a single device that combines an PLB or Epirb with a VHS MOB signal. Something like this..
vessels - Mobilarm V100 water-activated personal locator beacon - Team Australia - DMO



Added to a PLB. I'm amazed there isn't such a device on the market as having both functions in a single small device people can wear at all times would be a great thing I think.


Si
__________________
simonpickard is offline   Reply With Quote
Old 16-09-2012, 10:27   #6
Registered User
 
jeremiason's Avatar

Join Date: Oct 2010
Location: Punta Gorda, Florida
Boat: Sea Ray 270
Posts: 1,427
Images: 2
Send a message via ICQ to jeremiason Send a message via Yahoo to jeremiason Send a message via Skype™ to jeremiason
Re: EPIRB or PLB info direct to boat?

Simon

Many compnies have been working on various MOB alarms for years using both proximaty and radio devices... Raymarine has a radio proximaty alarm that sounds when it losses the signal of the wear's unit and marks a spot on the chartplotter...
Other companies have developed personal EPIRBS.

I am a safety freak and see applications for the Mobilarm Device and some disadvantages.

The advantages are easy.. Anything that helps locate a person in the water is a good thing, this device could help you get back to someone even in heavy seas. It relies on VHF Digital Selctive Calling, which is a good means to transmit data, including your GPS coordinates.

The problem I see with this paticular device is, again, that it relies on VHF Radio, which we all know is basically a line of sight device.

A person in the water with a VHF radio will transmit a much shorter distance than say a person standing on the deck of a boat, 6 feet above the water or better anantenna mounted on top of the mast.

The range of this unit would be further compromised if the transmitter was under water, say hanging from a belt of an unconcious person or if their were large waves blocking the signal.

The company claims a two to ten mile range, but the unit transmits at 1 Watt, so I think they are being little optomistic...

Otherwise, it sounds like a great tool, but I would not call it the Holly Grail of MOB devices.
__________________
Tom Jeremiason
Punta Gorda, Florida

jeremiason is offline   Reply With Quote
Old 16-09-2012, 10:31   #7
Registered User
 
xymotic's Avatar

Join Date: Dec 2007
Posts: 1,076
Re: EPIRB or PLB info direct to boat?

you can directly track a PLB/EPIRB but my understaning is that these devices are very $$$$$

RT-500-M SAR Direction Finder System for Rescue Missions at Sea - RHOTHETA
__________________
xymotic is offline   Reply With Quote
Old 16-09-2012, 11:13   #8
Moderator
 
Paul Elliott's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Posts: 3,861
Images: 4
Re: EPIRB or PLB info direct to boat?

I have the ACR ARX-50 beacon receiver (unfortunately this product has been discontinued). This receiver will sound an alarm, and trigger the MOB input to my chartplotter, when it receives the 121.5 MHz beacon from one of my crew's PLBs.

What it *won't* do is receive the position data that the beacon is transmitting on 406 MHz. When the alarm goes off all I know is that the MOB is somewhere in my wake. I figure that the sooner I know about a MOB the better, so this is still very useful information. The satellites are no longer looking for the 121.5 MHz beacon, but this signal is still used by SAR personnel to home in on the victim.

There are beacon receivers with directional antennas that can be used to locate the victim. These aren't cheap. The PLB is not automatically activated, so the MOB needs to trigger it manually. There are some MOB devices that transmit this beacon automatically.

I do think that the AIS MOB beacons (Kannad SafeLink R10) will become the best solution. In some cases these can be automatically triggered, the signal will be picked up by any AIS receiver, and will show the victim's updated location. The AIS beacon will not be received by the emergency satellites (in contrast to the PLB).

What I want is a small device that can be worn by each crewmember, which has:
1) DSC-enabled VHF transceiver
2) AIS emergency beacon
3) PLB
5) Long battery life
6) It floats
7) Automatically activated (delayed or manual PLB activation)

I can get each of these now, but my crew would sink if they had to carry it all. I don't expect to see such a combined device anytime soon.

Of course the best MOB solution is to stay on the boat. That's why we wear PFDs with harness, and tether on.
__________________
Paul Elliott, S/V VALIS - Pacific Seacraft 44 #16 - Friday Harbor, WA
www.sailvalis.com
Paul Elliott is offline   Reply With Quote
Old 16-09-2012, 12:43   #9
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,028
Re: EPIRB or PLB info direct to boat?

Simon, the PLB or EPRIB is sending a digital signal on 406MHz, and considering that most of them use simple whip antennas the signal should be broadcast just as well on the sea surface as it is up to the satellites.

Which means a "simple" 406MHz receiver, feeding into a computer or dedicated digital module, would be able to display the message sent out by the PLB. I would expect that there is sucha piece of gear, possibly with a $10,000 price tag on it, already sold and used by the PLB/EPIRB manufacturers as part of their standard quality control equipment. They've got to actually send and read a message from each unit in order to be sure it works, so one hopes they are doing that, and the equipment is available from some vendor.

Odds are it will be cheaper to buy a separate MOB locator system though. There are also all sorts of inexpensive "luggage" alarms on the market, as low as $50 US, that sound an alarm whenever the "luggage tag" wanders more the fifty feet away. So if someone goes over, it would alarm almost instantly. Won't help you track them--but it will quickly and cheaply tell you there's a MOB.
__________________
hellosailor is offline   Reply With Quote
Old 16-09-2012, 13:25   #10
Registered User
 
jeremiason's Avatar

Join Date: Oct 2010
Location: Punta Gorda, Florida
Boat: Sea Ray 270
Posts: 1,427
Images: 2
Send a message via ICQ to jeremiason Send a message via Yahoo to jeremiason Send a message via Skype™ to jeremiason
Re: EPIRB or PLB info direct to boat?

Quote:
Originally Posted by Paul Elliott View Post
I have the ACR ARX-50 beacon receiver (unfortunately this product has been discontinued).

The satellites are no longer looking for the 121.5 MHz beacon, but this signal is still used by SAR personnel to home in on the victim.
Paul

There is a reason they dicontinued the unit... The Unitied Nations abandond the 121.5 MHz Search & Rescue Sstem almost three years ago and is no longer being used by most search and rescue units, including the USCG...

Here is a Fact Sheet from the USCG explaining the discontinued used of 121.5 MHz
__________________
Tom Jeremiason
Punta Gorda, Florida

jeremiason is offline   Reply With Quote
Old 16-09-2012, 14:49   #11
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,028
Re: EPIRB or PLB info direct to boat?

Tom, do you think the USCG and others (CAP, military) have actually pulled their old 121.5 rdf equipment from aircraft? As opposed to leaving it in place and using all available options and assets when they go out on SAR?

Some of those crews have velcro'd Garmins in their cockpits, the aircraft sometimes predate GPS and it ain't cheap to formally upgrade avionics.
__________________
hellosailor is offline   Reply With Quote
Old 16-09-2012, 15:08   #12
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
A standard PLB or EPIRB signal does not contain any location information. It only contains a digital ID. The satellite pass determines the location by doppler calculation. The pulsed digital 406mhz signal is very difficult to direction find as well. Hence the reason 121mhz is still used on SARTs.

Obviously GPIRBs send out an encoded location as well as ID.

The best devices on the horizon For local emergency are AIS SARTs. or AIS mob devices.

Dave
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 16-09-2012, 15:28   #13
Registered User
 
jeremiason's Avatar

Join Date: Oct 2010
Location: Punta Gorda, Florida
Boat: Sea Ray 270
Posts: 1,427
Images: 2
Send a message via ICQ to jeremiason Send a message via Yahoo to jeremiason Send a message via Skype™ to jeremiason
Re: EPIRB or PLB info direct to boat?

Quote:
Originally Posted by hellosailor View Post
Tom, do you think the USCG and others (CAP, military) have actually pulled their old 121.5 rdf equipment from aircraft? As opposed to leaving it in place and using all available options and assets when they go out on SAR?

Some of those crews have velcro'd Garmins in their cockpits, the aircraft sometimes predate GPS and it ain't cheap to formally upgrade avionics.
In 2000, International Cospas-Sarsat Program announced that they were phasing out 121.5 MHz in 2009.

In other words people had 9 years to purchase new 406 MHz EPIRBs.

As the drop dead date approched, the US Coast Guard did a PR campaign that wouuld have made a politican happy.

121.5 MHz compared to 406 MHz units is like comparing a rotary dial telephone to a Sat Phone...

121.5 MHz units were very inaccurate and since you had to use triangulation, it sometimes took hours to locate a unit. By contrast the 406 unit broadcasts a serial number and it's Lat/Long. As you know the serial number when referenced provides incredible detail about you and your vessel, which aids search & rescue.

As a result, no one in the Maritime and Aviation industries are carrying 121.5 MHz receiving units any longer and no satellites are listening.
__________________
Tom Jeremiason
Punta Gorda, Florida

jeremiason is offline   Reply With Quote
Old 16-09-2012, 15:52   #14
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Quote:
Originally Posted by jeremiason

In 2000, International Cospas-Sarsat Program announced that they were phasing out 121.5 MHz in 2009.

In other words people had 9 years to purchase new 406 MHz EPIRBs.

As the drop dead date approched, the US Coast Guard did a PR campaign that wouuld have made a politican happy.

121.5 MHz compared to 406 MHz units is like comparing a rotary dial telephone to a Sat Phone...

121.5 MHz units were very inaccurate and since you had to use triangulation, it sometimes took hours to locate a unit. By contrast the 406 unit broadcasts a serial number and it's Lat/Long. As you know the serial number when referenced provides incredible detail about you and your vessel, which aids search & rescue.

As a result, no one in the Maritime and Aviation industries are carrying 121.5 MHz receiving units any longer and no satellites are listening.
Not correct. Standard 406mhz epirbs and PLBs still use the satellite Doppler calulations. The 406 signal is pulsed digital encoded and is stronger and more stable. Hence the satellite can calculate the position more accurately. Of course the digital encoding supports gps derived lat lon so if you buy a GPIRB you will make use of that. These location signals are decoded by a Inmarsat geo stationary satellite.

Note that even with a GPIRB the fix requires two Doppler fixes first even if the gps signal is available. The alert is not raised on the gps component alone. So while the accuracy is improved with a GPIRB, the delay to first fix and hence alert is not.

Dave
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 16-09-2012, 17:09   #15
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,330
Re: EPIRB or PLB info direct to boat?

OK, let's put some EPIRB / PLB / ELT myths to bed. There is a lot of misinformation about this subject, possibly I suspect, because very few of us have ever really used one and most of our information comes from the salesman, the brochure, over a beer or the infamous internet. We certainly don't use them on a daily basis - good thing too I guess - .

Also there is a marriage of new and old technology which adds confusion to the average punter.

1. 121.5 MHz has NOT been phased out as SAR tool. What HAS been phased out is the detection by satellite of this signal, i.e. this frequency plays NO part in the original detection of beacon activation by a satellite, nor does it play any part the initial position analysis by Doppler effect. However 121.5 MHZ is the only frequency available to home in on the final position of the beacon (using standard VHF DF techniques). The 406 transmission is not suitable for standard DF techniques, it being a short pulse (~500 mS) transmitted ~ every minute.

2. All currently available beacons therefore transmit on both frequencies and I am not aware of any plans to change that.

3. The propagation of the transmissions is limited to Line of Sight (LOS). However, you must consider the height of both the transmit antenna and the receive antenna. As the transmit antenna is effectively at sea level, it is the height of the receive antenna that gives the effective range. Thus a 1 watt transmission is still effective at 10 to 20 miles for a aircraft receiver say a 1 or 2 two thousand feet. Of course, the range is greatly reduced if the receiver is at deck level, I am guessing it would be about 2 or 3 miles in real usage.

It is worth repeating that beacon with an embedded GPS (aka GPRIB) is so much superior in giving a precise location that unless one is really strapped for funds, it is a no-brainer.
__________________

__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Reply

Tags
epirb

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 16:22.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.