Best signaling devices from the searcher’s point of view - update

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This may have been corrected later in this thread... Once you activate your PLB (not a test) it continues to transmit your position periodically - usually relayed through the NOAA facility in Virginia. Frequency of 406 MHz pings to the satellite will depend on the model. Keep the antenna deployed and vertical to assist this. Do not turn it off to "save the battery" since it is also transmitting on the 121.5 MHz homing frequency and a helicopter you may not see or hear could be using that signal to home in on you at that time. Turning it off to save the battery defeats that signal.

The battery test protocol is not something you do more than at most monthly - perhaps before a big trip while at home next to your registered contact numbers in case you do inadvertently trigger an alert.

Nautilus ceased making the VHF version of the lifeline because those frequencies were never intended for non-marine use - and they only transmitted on one frequency which is no longer allowed. If you still have one they are really only good for the "we can see the boat but they can't see us scenario" anyway. You can carry a tiny marine VHF in a canister instead. Like the icon m24 M24 VHF Marine Transceiver - Specifications - Icom America

The new Nautilus AIS function is actually misleading to me because so few dive boats actually have AIS at all. So its not functional to activate global SAR like a PLB and not necessarily useful to even notify the dive boat you can see but can't see you. I think those are a false sense

Two last comments, the dive-alerts are totally useless. You cant hear them any further than a whistle - which is already fairly short range over any kind of boat engine noise. Lastly fluorescein dye is harmless.
I talked to Ryan Sawatsky of Nautilus Marine Rescue GPS: Official Website via Live Chat and emails about the new version of Nautilus, called Marine Rescue GPS (MRG). According to him, it will still be sending out distress signal in VHF range (156-174 MHz) via DSC (156.525 MHz) & AIS (161.975 and 162.025 MHz) with MID code, similar to MMSI code, where the first 3 digits being of MID are 972, the code for MOB (Man-Over-Board). The alert signal goes out with GPS longitude & latitude coordinates of the distress signal.

The differences between the old generation Nautilus Lifeline (NLL) and MRG are:
1. NLL is 2x bigger than MRG
2. NLL has built-in VHF 2-way radio. MRG has no VHF 2-way radio.
3. NLL has built-in USB rechargeable battery. MRG does not come with batteries. You need to buy & install two CR123 3V Lithium batteries
4. NLL will send out VHF distress signal via DSC with GPS. MRG will send out VHF distress signal via both DSC & AIS + GPS longitude & latitude coordinates.

AIS in liveaboards is more common than what you think.

I was on La Galigo (Raja Ampat, Indonesia) last November. They have AIS.

I was on Palau Aggressor II last December, where they have, not only AIS, but also lend MRG to their guests free of charge (FOC).

This coming December I’ll be in Maldives Aggressor II. They will also lend MRG to their guests FOC.

I’ll be on Nautilus Under Sea (Socorro, Mexico) in late December this year. They’ll lend the MRG to their guests obviously.

I’ll be on Blue Manta (Ring Of Fire, Indonesia) in September 2019. They have AIS.

Ferox (Malpelo, Colombia) has AIS. They lend McMurdo S10 PAB (Personal AIS Beacon) to their guests.

Would you think all of these six liveaboards investing lots of money on AIS & PAB to create a false sense on their guests?

I was on Mike Ball’s Spoilsport (GBR) in November 2016, which at least has DSC since they lend NLL to their guests. So did Galápagos Master in December 2016. I’ll be on Argo (Cocos, Costa Rica) in September this year & they’ll lend NLL to their guests.
Once again you are limited to VHF (156-174 MHz) reception range of 5km line-of-sight in calm seas and fair weather conditions, which is the major fact that Nautilus fails to disclose about all their current products. If no ships or land based tower antenna stations are out there in VHF range to receive your MRG signal, then nobody knows where you are.

This is the problem that arises when you try to apply a yachtsman/sailing crew Man-Overboard (MOB) local contingency & VHF technological solution to the totally different and delayed instance of the missing-at-sea/adrift diver scenario.

Where divers get confused in the application, and assume "instant" local alert and rescue capabilities of an AIS/DSC VHF radio unit (i.g. current Nautilus Products like their Marine Rescue GPS), over a 406 MHz PLB is in the classic MOB (Man Overboard) Scenario:
Tactically this is fine for example, if you're crewing a sailing vessel in the biennial Transpacific Yacht Race from San Pedro Calif to Honolulu Hawaii, and you fall MOB during rough seas at night: Along with your crew, there will be anywhere from twenty to forty or so sailing yachts out there with AIS/DSC within VHF range in the otherwise trackless open Pacific Ocean ready to immediately assist in picking you up.

AIS/DSC VHF MOB devices are not meant to replace but rather augment PLBs. That said, since they alert nearby AIS-equipped vessels, such as the boat from which the person fell overboard, to assist in the search-and-rescue effort, these devices can reduce rescue times substantially. A PLB, on the other hand works worldwide -well beyond VHF range- to summon rescuers. It’s important to keep a PLB around if venturing far out to sea and away from other boaters.

A Lost-at-Sea/Missing Diver can be considered a special case of a "delayed" MOB Scenario: Delayed in the sense that an elapsed normal recreational depth dive time is about 50 minutes to an hour -->if the Diver surfaces after an hour and does not see any sign of the diveboat, then the Diver has to manually call or activate a VHF DSC Distress Beacon such as the Nautilus Lifeline first generation or current Marine Rescue GPS, but the caveat still being the limited range of the VHF signal along with hoping there are other boats or land stations in the vicinity with VHF transceiver reception capability. Again, if you're at a remote divesite hundreds of kilometers away from the commercial shipping lanes or land VHF receiving stations, then the direct to satellite PLB distress beacon is your last resort.

Again IMO/IME, a tropical squall & thunderstorm in zero visibility is the most common post-dive surfacing condition with a potential adrift lost-at-sea worst case scenario which you should smartly prepare yourself beforehand with at least a PLB:

A Nautilus Marine Rescue GPS/VHF Radio Transceiver Beacon may not save you in this instance due to "rain fade" signal attenuation, and the chances that any boats with marine VHF Radio DSC/AIS capability may be out of reception range of your distress signal by the time the squall clears and the weather & sea state moderates again. . .

Nautilus Marine Rescue GPS and Nautilus PLB
 
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Once again you are limited to VHF (156-174 MHz) reception range of 5km line-of-sight in calm seas and fair weather conditions, which is the major fact that Nautilus fails to disclose about all their current products. If no ships or land based tower antenna stations are out there in VHF range to receive your MRG signal, then nobody knows where you are.

This is the problem that arises when you try to apply a yachtsman/sailing crew Man-Overboard (MOB) local contingency & VHF technological solution to the totally different and delayed instance of the missing-at-sea/adrift diver scenario.

Where divers get confused in the application, and assume "instant" local alert and rescue capabilities of an AIS/DSC VHF radio unit (i.g. current Nautilus Products like their Marine Rescue GPS), over a 406 MHz PLB is in the classic MOB (Man Overboard) Scenario:
Tactically this is fine for example, if you're crewing a sailing vessel in the biennial Transpacific Yacht Race from San Pedro Calif to Honolulu Hawaii, and you fall MOB during rough seas at night: Along with your crew, there will be anywhere from twenty to forty or so sailing yachts out there with AIS/DSC within VHF range in the otherwise trackless open Pacific Ocean ready to immediately assist in picking you up.

AIS/DSC VHF MOB devices are not meant to replace but rather augment PLBs. That said, since they alert nearby AIS-equipped vessels, such as the boat from which the person fell overboard, to assist in the search-and-rescue effort, these devices can reduce rescue times substantially. A PLB, on the other hand works worldwide -well beyond VHF range- to summon rescuers. It’s important to keep a PLB around if venturing far out to sea and away from other boaters.

A Lost-at-Sea/Missing Diver can be considered a special case of a "delayed" MOB Scenario: Delayed in the sense that an elapsed normal recreational depth dive time is about 50 minutes to an hour -->if the Diver surfaces after an hour and does not see any sign of the diveboat, then the Diver has to manually call or activate a VHF DSC Distress Beacon such as the Nautilus Lifeline first generation or current Marine Rescue GPS, but the caveat still being the limited range of the VHF signal along with hoping there are other boats or land stations in the vicinity with VHF transceiver reception capability. Again, if you're at a remote divesite hundreds of kilometers away from the commercial shipping lanes or land VHF receiving stations, then the direct to satellite PLB distress beacon is your last resort.

Again IMO/IME, a tropical squall & thunderstorm in zero visibility is the most common post-dive surfacing condition with a potential adrift lost-at-sea worst case scenario which you should smartly prepare yourself beforehand with at least a PLB:

A Nautilus Marine Rescue GPS/VHF Radio Transceiver Beacon may not save you in this instance due to "rain fade" signal attenuation, and the chances that any boats with marine VHF Radio DSC/AIS capability may be out of reception range of your distress signal by the time the squall clears and the weather & sea state moderates again. . .

Nautilus Marine Rescue GPS and Nautilus PLB

That’s why I have, DSMB, Dive Alert, PAB & PLB.

DSMB
As you mentioned in Where do I put my (D)SMB? about launching DSMB at depth, as soon as you get blown away by current.

Dive Alert
In such squalls loud sound may be helpful to use.

PAB
For faster response within VHF range as planned with the liveaboard crew.

PLB
For alerting device as the last resort, when other alerting devices fail.
 
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So potentially have the opportunity to get a Nautilus Gen 1 for $50 (used but working), still a worthwhile idea? Currently have a DSMB, whistle, and signal mirror. So this would be my first "tech" for rescue. Primarily would be used for diving inside the US, liveaboards are not on my mind (we haven't done one yet and not in the foreseeable future). A PLB is on my gear wish list, but probably only will be purchased before a major non-US trip.
 
So potentially have the opportunity to get a Nautilus Gen 1 for $50 (used but working), still a worthwhile idea? Currently have a DSMB, whistle, and signal mirror. So this would be my first "tech" for rescue. Primarily would be used for diving inside the US, liveaboards are not on my mind (we haven't done one yet and not in the foreseeable future). A PLB is on my gear wish list, but probably only will be purchased before a major non-US trip.

$50 is a great deal! I think it’s a good start. I treat it as the smallest underwater 2-way VHF radio with built-in waterproof canister. You may want to check if the battery is still good. Talk to @divinh
 
Great discussion. I looked at all available options when selecting the best PLB for our guests. The deciding factor was time. With the currents at Malpelo we need to know position immediately. When activated it shows up on the Ferox's AIS as well as electronic chart plotter as well as the AIS receiver's in all three of our RIB's. Bearing and distance facilitate a fast rescue in poor visibility. It is also helpful that it gives us GPS positon and even has a flashing light.

It is not perfect and not a substitute for an EPIRB but it is the best for our operating conditions and the equipment we have available to conduct a search and rescue.

Another key factor and maybe a topic for another thread is training. You can have great signaling devices but if you do not have a crew trained to carry out a search and rescue then you are limiting your chances dramatically.

We do not want to provide a false sense of security. Our goal is to minimize risk while diving at remote locations like Malpelo.

Safe diving,

Tony
 
Great discussion. I looked at all available options when selecting the best PLB for our guests. The deciding factor was time. With the currents at Malpelo we need to know position immediately. When activated it shows up on the Ferox's AIS as well as electronic chart plotter as well as the AIS receiver's in all three of our RIB's. Bearing and distance facilitate a fast rescue in poor visibility. It is also helpful that it gives us GPS positon and even has a flashing light.

It is not perfect and not a substitute for an EPIRB but it is the best for our operating conditions and the equipment we have available to conduct a search and rescue.

Another key factor and maybe a topic for another thread is training. You can have great signaling devices but if you do not have a crew trained to carry out a search and rescue then you are limiting your chances dramatically.

We do not want to provide a false sense of security. Our goal is to minimize risk while diving at remote locations like Malpelo.

Safe diving,

Tony
Again. . . AIS/DSC alert beacons require line-of-sight VHF terrestrial reception with a limited range at best 5km. If the mothership Ferox and all three of your.RIBS go searching beyond range in the wrong direction, you will just as quickly lose track of that adrift diver.

PLB 406MHz technology is direct to satellite distress signal that identifies the missing diver by name and determines the originating signal location anywhere in the world. It is up to the designated Emergency Contact associated with activation of that PLB to provide vital information to government SAR authorities, as well as local dive operation cellphone contact numbers, so the exact GPS coordinates of the missing diver can be relayed to all search parties to effect a timely rescue.

Finally all divers should not rely solely on Dive Operation provided AIS technology locator units, but also should purchase their own PLB 406MHz device along with a depth proof canister container, as last chance backup, that when activated in an emergency uniquely identifies them and fixes their position anywhere on the globe.
 
Again. . . AIS/DSC alert beacons require line-of-sight VHF terrestrial reception with a limited range at best 5km. If the mothership Ferox and all three of your.RIBS go searching beyond range in the wrong direction, you will just as quickly lose track of that adrift diver.

PLB 406MHz technology is direct to satellite distress signal that identifies the missing diver by name and determines the originating signal location anywhere in the world. It is up to the designated Emergency Contact associated with activation of that PLB to provide vital information to government SAR authorities, as well as local dive operation cellphone contact numbers, so the exact GPS coordinates of the missing diver can be relayed to all search parties to effect a timely rescue.

Finally all divers should not rely solely on Dive Operation provided AIS technology locator units, but also should purchase their own PLB 406MHz device along with a depth proof canister container, as last chance backup, that when activated in an emergency uniquely identifies them and fixes their position anywhere on the globe.

I agree that carrying both is ideal and as I stated in my previous post:

"It is not perfect and not a substitute for an EPIRB but it is the best for our operating conditions and the equipment we have available to conduct a search and rescue."
 
And so is your vessel equipped with an EPIRB? You know, in case you have a through hull fitting fail. Do you have any seacocks? When's the last time you turned them?
No epirb and no through hull fittings, why would you drill a hole in a perfectly good hull, my deck drains though scuppers.
 
https://www.shearwater.com/products/perdix-ai/

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