EPIRB and AIS

[Cargile]

About to purchase our 1st EPIRB. I see some are advertised with AIS. Our boat does not have AIS and don't plan on purchasing a unit. I understand an AIS has to be registered with some gov't agency? So of what use is an EPIRB w AIS in my situation? or is it an additional expense? Thanks

[Portage_Bay]

Both EPIRB and AIS need to be registered. In the US EPIRB with NOAA, AIS with FCC or other approved agency.

EPIRB uses satellites to broadcast your emergency. There are variouis EPIRBs available. If satellite is all the EPIRB has then rescuers get close to you but do not have exact your location and have to spend some time searching for you usually looking for a strobe on the EPIRB.

Some EPIRBs have GPS and or AIS. Either will boradcast your exact GPS coordinates cutting the search time to a minimium.

With a GPS enabled EPIRB as far as I know your coordinates need to go the satellite then be communicated back to the rescuers. With an AIS enabled EPIRB your coordinates will be near real time position broadcast. GPS because it uses satellites is not range limited. AIS uses VHF frequencies and is by it's nature range limited.

You have to evaluate your cruising area and closeness to reescue agencies to make your best decision.

[psneeld]

Though I have no personal experience with them, a quick read to me suggests a great idea.

Very few vessels, including SAR units, have great or even any direction finding aboard so the AIS included version allows ANY vessel with AIS to come to your assistance quickly if they are AIS receive or transceive.

Worth every penny and the effort to register no matter how complicated.

[C lectric]

But if you don't register it you have hampered the usefullness. Unregistered is better than nothing though.

[DDW]

If an EPIRB is unregistered, SAR will still be alerted but the response may be very slow. Since most of their alerts are false alarms, time is spent vetting the device to see if it is real. With a registered device they will call the registered emergency contact numbers for example to verify you are actually out of the water. Unregistered thew may attempt to contact the last registered emergency contacts, but an unregistered is a second priority.

In my opinion AIS is better in a populated area, more likely to get a quick response. In a sparsely travelled area, AIS is unlikely to be heard.

There is a third category, and that is the satellite messengers (such as the InReach) which fill some of this need and are useful for other things.

[SoWhat]

EPIRB will send signal via satellite to USCG. Unlimited range so perfect of you go offshore.

AIS will send signal to any boat and USCG within VHF range. AIS has not been widely adopted by pleasure boats in some areas so response may be limited but probably OK if you boat in crowded areas.

Any modern marine radio will have DSC and if connected to chart plotter will also send out VHF signal to USCG. Again, VHF is range limited.

And there is always 911 on your cell phone.

If you travel frequently over long distances then all 3 methods should be utilized. If you need help, you need it quickly, so the more methods the better. Obtaining the required MMSI number or registering the epirb is an easy and quick process.

[Cigatoo]

There is AIS and DSC. Both work through VHF transmission. AIS does not transmit a distress call but is highly useful in identifying other vessels and also making yourself seen to other vessels. DCS is usually a part of your VHF radio. The red distress button is one part of it. When the red distress button is pushed it will send a distress signal over your VHF to anyone monitoring that frequency. IE Coast Guard and nearby boats. Very important that you have your MMSI number Pre programmed into the radio so that the signal is identifiable to those receiving.
EPIRB will send distress signal via satellite. MMSI has to be programmed here also. If you are boating in a remote area EPIRB would be my first choice. In less remote areas DCS would be my first choice. Having both can’t hurt.

[psneeld]

These are pretty new...everyone done their homework? Not sure based on some parts of some posts.....

https://www.hodgesmarine.com/acr2852...All%20Products

Acr Globalfix V5 Cat 2 Gps Ais Epirb W/Return Link Service & Mobile App
GlobalFix™ V5 Cat 2 GPS AIS EPIRB with Return Link Service & Mobile App

The ACR GlobalFix V5 EPIRB combines 406 MHz satellite connectivity with Automatic Identification System (AIS) functionality. This means that when the EPIRB is activated not only does it transmit your emergency signal to the global Cospas Sarsat satellite rescue system, but it broadcasts an AIS safety message on VHF-frequencies that can be seen immediately by any AIS-equipped vessel nearby. Other great features include Return Link Service (RLS) technology that provides visual confirmation to the user that their distress message has been received, a 121.5 MHz homing signal, and visible and infrared strobe lights for easy target identification at night or in poor visibility. Another feature is Near Field Communication (NFC) which allows users to monitor their EPIRB using a smartphone App. ACR is the global leader in marine safety and rescue technology and the GlobalFix V5 GPS EPIRB with AIS combines the durability and reliability they are known for with advanced technology designed to speed rescue response time.

[Ka_sea_ta]

When I was in the cg and one of the stations would receive a distress signal, IRC these could be satellite but 121.5 not 406mhz. We would launch and once in the general area we would then use df capabilities at a 121.5 mhz.... I'm pretty sure things have changed now with GPS coordinates embedded in the 406 mhz distress message.

[psneeld]

https://www.yachtworld.com/research/...ter%20accuracy.

An EPIRB is registered to the vessel and transmits a short burst of data when it’s activated. Most EPIRBs today function on the 406MHz bandwidth and their signal can be picked up anywhere on the globe as opposed to the older and less expensive 121.5 MHz units whose signal was designed to be picked up by airplanes flying overhead. Some EPIRBs include both bands and use the 121.5 MHz as an additional homing signal for greater accuracy. Some also have integrated GPS to broadcast not only distress but also a specific location and they’re called GEPIRBs.

[DDW]

Originally Posted by Cigatoo

There is AIS and DSC. Both work through VHF transmission. AIS does not transmit a distress call but is highly useful in identifying other vessels and also making yourself seen to other vessels.

The AIS MOB beacons broadcast a DSC distress call and also AIS beacon information. In theory, everyone within range will get a DSC distress alert along with the AIS information.

Originally Posted by psneeld

Some also have integrated GPS to broadcast not only distress but also a specific location and they’re called GEPIRBs.

Almost any new EPRIB you buy these days will be 406 MHz and have GPS. For example ACR does not sell one without GPS. A GPS receiver module is <$5 these days, almost criminal not to put one in.

[23435ps]

There is also one PLB/AIS approved in the US that just went on the market: https://www.acrartex.com/products/re...ocator-beacon/. The PLB capability (same as EPIRB but with less battery life) alerts the SARSAT/COSPAS system and will provide a distress alert to the appropriate SAR system. The AIS capability transmits the local VHF-FM alert that can be picked up by nearby AIS receivers. Thus you have what is in effect a "global alert" and a "local alert" functionality. The unit also transmits on the aircraft distress UHF frequency which provides a homing signal for SAR aircraft. ACR has the only one so far but I am sure the other PLB manufacturers will get there's soon! The PLB/AIS is also designed to be attached to a lifejacket.

[psneeld]

Originally Posted by 23435ps

There is also one PLB/AIS approved in the US that just went on the market: https://www.acrartex.com/products/re...ocator-beacon/. The PLB capability (same as EPIRB but with less battery life) alerts the SARSAT/COSPAS system and will provide a distress alert to the appropriate SAR system. The AIS capability transmits the local VHF-FM alert that can be picked up by nearby AIS receivers. Thus you have what is in effect a "global alert" and a "local alert" functionality. The unit also transmits on the aircraft distress UHF frequency which provides a homing signal for SAR aircraft. ACR has the only one so far but I am sure the other PLB manufacturers will get there's soon! The PLB/AIS is also designed to be attached to a lifejacket.

Thanks, hopefully some will do a bit more research to get the big picture on what is truly available.

[Cigatoo]

Transmission of AIS by an EPIRB is a great enhancement. I didn’t realize that was available. So I guess I will stand as corrected / educated. My post was to distinguish the 3 different technologies and their different strengths. Most importantly I didn’t want someone to think AIS would suffice as a distress mechanism. Learn something new every day.

[psneeld]

I apologize for my shortness and brusk attitude sometimes.

Most posters do their best to post good info. Some not so much as darn near every post of theirs has incorrect info in it.

Most of the time, if I have no personal info on the subject or it's one I haven't been personally involved with, I try a little research before I post. Keeps down the confusion and misinformation.... in addition to creating mindless discussions other posters have to wade through. Even in this case I am not well read on the subject...but my post/links are designed to get truly interested persons tuned in to their own research on the subject.

I do have enough experience to know tidbits about quite a few subjects and know that electronics tech changes every year and be careful to not report only what I knew last year.

Again, just a couple of minutes to double check a post's validity takes only a few minutes. Soapbox.... out.......

[Hippocampus]

My understanding is in open ocean, particularly beyond helicopter range, most MOB rescues are done by the boat you fell off of or a boat in your fleet or rally. In this setting AIS is a much more valuable aid than any gps based device. Our harness/pfd set ups have carried both a 24 hour epirb and a AIS but now you can get both in a single device. As well as the personal devices we carried a ship’s epirb. It was in a bracket so could be removed and carried into the liferaft if needed.
Believe in a coastal setting this is overkill and unnecessary expense. Realistically you can set off the personal devices sequentially so get at least 48h even with only two. The majority of rescue occurs with 24 hours. With AIS there’s two things to consider. Can your vessel see the signal generated by a MOB? Can the rest of the world see the signal? In a coastal or near shore (<200nm offshore) setting believe a ships epirb is unnecessary but each personal set up should carry a combined personal epirb/AIS and the ship should have AIS on its own antenna. Appropriate spare connections to allow the ships AIS unit to use the VHF antenna as well. Prior boat had both SSB and KVH satellite comms. Once again if coastal believe both are unnecessary. However if nearshore or open ocean at a minimum would carry some form of satellite communication. Ideally one that could carry both voice and data. My two cents. P.S.-combo personal units are on my Xmas list.

[Hippocampus]

https://www.lrse.com/collections/epi...-v5-category-i

https://www.lrse.com/collections/epi...-450-w-ais-rls

The second of these devices are personal epirb offering gps locators for at least 24h and AIS. Several vendors offer similar. Apparently things have changed since you retired. I continue to believe they are more than adequate for coastal near shore environments. My viewpoint is based on both professional and amateur opinions I’ve garnered.

[Hippocampus]

As an aside would give a +1 to ocens for offshore communications needs. Personally had the best experience with KVH, second with iridium products and not so much with globalstar. Understand starlink changes things now. But if going nearshore would add some form of satellite communication independent of a SAR request. Feel it’s a necessity if offshore. Believe in certain scenarios having that may even prevent the need for further outside help. Have used voice satellite to help me work through things like navigation instruments troubleshooting and repair, watermaker troubleshooting, medical issues such as obtaining salient information about crew from loved ones. Text is wonderful but when stressed or it’s real bumpy voice is very helpful. Also a +1 to LFSE. Talking with them is always an education. They service pros and amateurs so get sufficient feedback to make appropriate recommendations.
We are in the process of replacing all our PLBs with combo devices. So far the ACR device linked above seems the best bang for the buck for our current program.

[23435ps]

Originally Posted by Cigatoo

Transmission of AIS by an EPIRB is a great enhancement. I didn’t realize that was available. So I guess I will stand as corrected / educated. My post was to distinguish the 3 different technologies and their different strengths. Most importantly I didn’t want someone to think AIS would suffice as a distress mechanism. Learn something new every day.

The combined EPIRB (or PLB) / AIS were literally just approved (in the US) and hit the market only in the past couple of months. But your review of the the 3 very different technologies (and their pros and cons) is still very valid as many people will not have the combined units (if at all) or will still make the decision between different technologies.

[Hippocampus]

Another way to skin the cat is to keep your existing PLBs and add this handheld DSc vhf with AIS
ICOM IC-M94D AIS & DSC VHF RADIO.
Keep it charged and ready for the ditchbag. Sure a ships Epirb will go 48h but coastal/near shore likely not needed and if so set off the PLBs sequential. Current personal units tell you the request was received. Then the radio when you hear the helicopter or see the boat. Of course what you do is situationally specific. Likely radio battery life is sufficient in most coastal settings. Talking with active CG members think it likely more combo units will become available at both ship and personal levels and the transition to combo units will occur.