True for the old Nautilus Lifeline (NLL) on high failure rate, but not on the new one, that is called Marine Rescue GPS (MRG), that has 5 year warranty battery life & half the size of the old NLL. The MRG is now a bit smaller than the size of my old camera case containing my PLB1.
The MRG, although has no longer 2-way radio capability, it has both DSC & AIS. The old NLL has only the DSC, which is pretty much useless in Indonesian water if you are not in the path of big ships, according to
@IyaDiver
The AIS technology lets you load the ship MMSI. So, when you pull up the antenna & push the red button, the boat will know who you are & where you are. That’s why Palau Aggressor II are now renting MRG for free to its guests to carry it during the trip.
Time is of the essence due to the limited direct path distance of the radio signal. So, as soon as you come up to the surface & don’t see the dingy or see only tiny-weeny of the mother boat, you need to launch that little gizmo within minutes.
I’m going to get one of these MRG in addition to my PLB1. I’m going to check Blue Manta if they carry them for their guests to rent for my next trip to Indonesia (Ring of Fire: Maumere - Alor - Manuk - Banda - Ambon) that is known for the treacherous deep trench sea. If Blue Manta doesn’t rent MRG, at least I can load its MMSI to my MRG