Nautilus Lifeline Radio

[divinh]

AIS vs DSC

How AIS Works

"The system is backwards compatible with digital selective calling systems, allowing shore-based GMDSS systems to inexpensively establish AIS operating channels and identify and track AIS-equipped vessels, and is intended to fully replace existing DSC-based transponder systems."

"fully replace"... though I wonder if there's a lot of inertia from installed DSC systems that will make AIS take a long time to overcome...

 

[ScubaSteve85]

I don’t know if the 1st generation is better but some people think so, so I got a new 1st generation one for a very good price to play with and test out. There are still new 1st generations floating around some dive shops’ forgotten inventory.

So far I've been happy with mine, although thankfully I haven't had to test it out yet .I was able to snag a new one from a surf shop in Canada for a great price. Gotta love our neighbors to the north!

 

[Belzelbub]

I read that most modern VHF radios have DSC and since the liveaboard is a custom built boat that started operations in 2015, you would think they would have a fairly modern radio. My question is: Is it likely that they do have DSC and don't know it's there or not have it at all?

Correct. DSC has been required on all VHF radios sold in the US for quite some time (1999, I think). Not sure about other areas, though manufacturers may have phased out non-DSC radios in order to keep configurations down.

That said, despite almost all the radios out there having DSC capability, that doesn't mean they have enabled DSC. The vast majority of recreational boaters have not hooked up their DSC radios to take full advantage. Hopefully commercial boats have a higher take rate, but I'm not sure. To take full advantage of a DSC-enabled radio, you need to do two things. 1 is fairly easy, the other is a bit more difficult.

First, you need to get an MMSI and program it into your radio. This information would be sent to monitoring authorities in the event that the red button is pressed. Other information may or may not be sent depending on if the second thing is done.

Second, you need to connect the VHF to a GPS signal. Some VHFs have internal capability, so that part may be done. Even if this is the case, it's still a good idea to connect to a GPS chart plotter. Most chart plotters would be able to receive the distress signal and mark it on the screen provided the GPS is properly connected. Getting the GPS connected to the VHF is not the easiest thing in the world. Usually, this is done on the NMEA 0183 lines. Unfortunately, there hasn't been a standard color coding between VHF and GPS manufacturers for this. Basically, you need to connect the TX + wire on one device to the RX + wire on the other device, and vice-versa (sometimes, depending on GPS) The - versions of those wires also need to be dealt with. Basically, you need to get out the manual of both devices, and follow both sets of instructions. It can be a pain to do properly, so apart from my own boat, I don't have a lot of faith that it was done.

 

[divinh]

I was chatting with a diver at a meetup yesterday and he said that the liveaboard I signed up with might not have a VHF radio at all, but some kind of "marine radio"? He said that even if the boat was recently built, especially an Indonesian traditionally-built wooden-hulled one, it wouldn't get the latest electronics, due to cost and/or power requirements.

Basically, it sounds like both Nautilus models won't be useful in contacting the liveaboard I signed up for. I would be reliant on other boats for help.

 

[Dogbowl]

@divinh , Why don’t you try contacting the liveaboard to confirm?

Indonesia was discussed at length somewhere in this thread. IIRC, many Indonesian dive boats use cell phones! So yeah, these devices are only useful if the boat you’ll be on has the technology to support it. You may look into a PLB in addition, although in Indonesia it may or may not be useful - this, too, was discussed at length.

 

[Rred]

Indonesia is one of many places in the world where the short range of a US marine band VHF simply doesn't help. Indonesia doesn't have "coast guard" bases located every 30 miles, so they'd probably need to use HF, marine SSB, which can quickly be a $2500 install (and up) and require trained operators.

 

[divinh]

@divinh , Why don’t you try contacting the liveaboard to confirm?

Indonesia was discussed at length somewhere in this thread. IIRC, many Indonesian dive boats use cell phones! So yeah, these devices are only useful if the boat you’ll be on has the technology to support it. You may look into a PLB instead, although in Indonesia it may also not be that useful. Some believe it’s useful, others don’t think so.

I've contacted the liveaboard and asked about AIS and DSC and they said they had neither, which ruled out the 2nd gen Nautilus for me. I thought all radios had VHF, so was looking into getting a 1st gen Nautilus, but now that's unclear. The liveaboard does have satellite radio for emergencies, but that's not something I've seen for a diver.

My thought for emergencies is to try to contact the boat I came from first, as they're probably the closest to respond - DSMB/whistle/DiveAlert first after surfacing. Next, would be 1st gen Nautilus if VHF radio/DSC or 2nd gen Nautilus if AIS/DSC. Finally, PLB because my emergency contacts would need to be contacted (probably asleep when I'm active; other side of the world), then they would need to contact the boat to confirm true emergency and assist in relaying info or contacting local SAR - all this would take quite a while. (For Komodo, one diver drifted 25km in 5 hrs, so time is of the essence to reduce search area.)

 

[Dogbowl]

@divinh , looks like you’ve already thought of everything...

I can only think of one other thing that hasn’t been mentioned yet: do you pray?

Joking aside, Im also having a tough time choosing my emergency contacts. I don’t know anyone that picks up theirs phones anymore! Everyone just texts and messages these days! Even email is old school.

 

[divinh]

Indonesia is one of many places in the world where the short range of a US marine band VHF simply doesn't help. Indonesia doesn't have "coast guard" bases located every 30 miles, so they'd probably need to use HF, marine SSB, which can quickly be a $2500 install (and up) and require trained operators.

Ah, thank for the info! I guess that clarifies the meaning of "marine radio". Now, what to do...?

 

[divinh]

@divinh , looks like you’ve already thought of everything...

I can only think of one other thing that hasn’t been mentioned yet: do you pray?

Joking aside, Im also having a tough time choosing my emergency contacts. I don’t know anyone that picks up theirs phones anymore! Everyone just texts and messages these days! Even email is old school.

1st Gen Nautilus - rely upon other boats for VHF/DSC
2nd Gen Nautilus - rely upon other boats for AIS/DSC

Which is more likely in Indonesia? I don't know.

PLB - response time too long given amount of possible drift

Maybe just get one and hope to never have to use it?

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Whoever the emergency contact is, would he/she answer an unrecognized number, even if they're the kind to answer the phone? What about leaving the ringer on while sleeping? Even more questions!