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

[hammet]

Has anyone done any actual tests with the Nautilus?
VHF communication is line of sight meaning that if the you can't see the vessels you need to reach, you probably won't be able to transmit to them successfully. This is why VHF antennas are mounted on the masts of boats. Down at the surface of the water, your signal won't get very far due to the curvature of the earth. Even handheld VHF radios transmitting from the deck of a boat have a limited range of just a couple of miles or so. Transmission also becomes more difficult in a stormy seas where large waves may be present. That and the small power output of the device makes me wonder how reliable these devices are in an actual emergency situation.

That being said, I carry a PLB on my inflatable life jacket when sailing.
The great thing about a PLB is that (at least in the US), the Coast Guard will be quickly alerted. They will typically then announce a Security alert over VHF channel 16 which will be received by any police, harbor patrol, and any civilian vessels in the area while they mobilize their own rescue. And since the PLB signal goes directly up to the satellites, it is unaffected by wave action. I know if I press my PLB button, lights are going to go off on peoples consoles everywhere.

 

[Dan]

I just noticed that new PLB1 has “MEOSAR compatible” stamped on its picture. So, I dug more info about it & learned that Cospas-Sarsat has improved its capability in locating 406 MHz beacons by adding MEOSAR, as described in MEOSAR: New GNSS Role in Search & Rescue | Inside GNSS

“....For more than 30 years, since its initial deployment in 1982, the Cospas-Sarsat system has provided valuable emergency distress detection and location information to worldwide search and rescue operators and teams. As part of an international cooperation to make available a free-of-charge search and rescue (SAR) service, the system has been credited with assisting more than 37,000 people all around the world.

The system uses satellite-based payloads, hosted by low Earth orbit (LEO) constellations (LEOSAR), to detect and locate distress signals emitted by emergency beacons carried by mariners and aviators as well as by land-based users. Cospas-Sarsat has relied on its original LEO architecture since declaration of the system’s full operational capability (FOC) in 1985. It was complemented by geostationary (GEO) satellites (GEOSAR) in 1994.

Cospas-Sarsat has proven its efficiency. LEO satellites may locate beacons almost anywhere thanks to Doppler effect with a limited instantaneous coverage. The GEO satellites have a very wide field of view, which offers real-time detection but no possibility of independent location as the Doppler effect is negligible in GEOs.

To improve performance, the system is now undergoing a profound evolution called MEOSAR, which will add SAR capability to middle Earth orbit (MEO) satellites. By the end of this decade, Cospas-Sarsat will rely on a MEO/GEO space segment, replacing the LEO/GEO design, thanks to SAR payloads hosted by three GNSS constellations: GPS, Galileo, and GLONASS.

With numerous satellites, each with an Earth coverage or footprint significantly larger than the LEO satellites (about seven times larger), the MEOSAR constellations will enable an instantaneous and worldwide coverage. Distress beacons will be detected and located more quickly and accurately than today, in as little as one beacon burst, that is, about 50 seconds. The more efficient alert notices that result will directly contribute to the efficiency of rescue operations where time is critical.

In the first step of this evolution, and for obvious reasons like continuity of service, the current Cospas-Sarsat user segments will remain unchanged. The MEOSAR system will fulfill the SAR missions for more than the 1.4 million first-generation beacons already available, which were designed for the LEO constellation and therefore not optimized for the MEO case.

In the meantime, a substantial effort is being made to define a second-generation beacon compatible with MEOSAR, with updated operational and mission requirements, as well as to establish enhanced design requirements for user equipment. This creates a unique opportunity to design a signal, together with the associated ground station processing, that can fully exploit the numerous advantages of a MEO constellation. These include such factors as increased accuracy, availability, and robustness, together with simultaneous position and velocity determination, which are very useful for locating dynamic beacons onboard aircraft...“

So, for those of you who are still considering to get a PLB, make sure it is MEOSAR compatible.

 

[Celt]

I have no alert devices what so ever, if i cant make it back to my boat and cant save myself, im going to do the decent thing and drown.

 

[Dan]

I have no alert devices what so ever, if i cant make it back to my boat and cant save myself, im going to do the decent thing and drown.

Well, with 5000+ logged dives under your belt, you have beaten the odds of getting lost at sea without any alert devices. You know how to make it back to your boat. I wish I’d be that lucky to log 5000+ dives & be here to share my experience

 

[chillyinCanada]

I have no alert devices what so ever, if i cant make it back to my boat and cant save myself, im going to do the decent thing and drown.

While I certainly enjoyed the wry humor in your response, nonetheless, need to point out that a search will ensue in any event. Perhaps you could leave a note with a beacon floating in your absence? Note to read words to the effect: "Goodbye cruel world."

 

[Celt]

While I certainly enjoyed the wry humor in your response, nonetheless, need to point out that a search will ensue in any event. Perhaps you could leave a note with a beacon floating in your absence? Note to read words to the effect: "Goodbye cruel world."

Not a bad idea, but i prefer to concentrate all my efforts in not getting lost in the first place than trying to help would be searchers find me. The problem with backup plans is the primary plan is sometimes neglected.

 

[Celt]

Well, with 5000+ logged dives under your belt, you have beaten the odds of getting lost at sea without any alert devices. You know how to make it back to your boat. I wish I’d be that lucky to log 5000+ dives & be here to share my experience

My life long friend is 84 and still likes to dive.

 

[Dan]

Hopefully we won’t do like this 68-year-old man, who was lost at sea off the north Queensland coast overnight, counting his lucky stars while recovering from mild hypothermia in Townsville Hospital, after 17-hour floating at sea.

'Crazy luck': Missing Queensland diver found alive after nearly 18 hours lost at sea

"He's gone by himself, which is a bit naughty. He jumped in the water from his boat and then realised the current was so strong and he simply couldn't get back," Officer Griffiths said.

He has a PLB but forgot to bring it with him. SAR had to spend many hours to find him.

 

[chillyinCanada]

Not a bad idea, but i prefer to concentrate all my efforts in not getting lost in the first place than trying to help would be searchers find me. The problem with backup plans is the primary plan is sometimes neglected.

For the sake of your loved ones so that everyone knows to quit searching.

 

[Celt]

Hopefully we won’t do like this 68-year-old man, who was lost at sea off the north Queensland coast overnight, counting his lucky stars while recovering from mild hypothermia in Townsville Hospital, after 17-hour floating at sea.

'Crazy luck': Missing Queensland diver found alive after nearly 18 hours lost at sea

"He's gone by himself, which is a bit naughty. He jumped in the water from his boat and then realised the current was so strong and he simply couldn't get back," Officer Griffiths said.

He has a PLB but forgot to bring it with him. SAR had to spend many hours to find him.

I would give up diving if i became so careless that i would neglect to check for surface current and get in the water without being tethered to my boat