PLBs Can Save Your Life

[Dan]

Does anyone know anything about the following plb? It mentions 300m ...

Crewsafe V200

From reading the description it is similar to the Nautilus Marine Rescue GPS, another words, it's a PAB (Personal AIS Beacon) transmitting AIS man over board signal via VHF. It is not a PLB that transmits 406 MHz directly to SAR satellite.

I carry both PLB & PAB and use them whichever appropriate.

Many liveaboards that take divers to dive in open ocean issue PAB to their guests, such as Palau Aggressor, Maldives Aggressor, Nautilus Undersea, Argo, etc.

PAB has advantage of quick local response by boat in the area, while PLB would be a bit longer due to global nature as the signal would be sent up to the SAR satellites and to be received & verified by Mission Control Center before actual local SAR team would be mobilized.

 

[Protondecay123]

From reading the description it is similar to the Nautilus Marine Rescue GPS, another words, it's a PAB (Personal AIS Beacon) transmitting AIS man over board signal via VHF. It is not a PLB that transmits 406 MHz directly to SAR satellite.

I carry both PLB & PAB and use them whichever appropriate.

Many liveaboards that take divers to dive in open ocean issue PAB to their guests, such as Palau Aggressor, Maldives Aggressor, Nautilus Undersea, Argo, etc.

So what is the transmit power for the VHF? Maybe I overlooked it, but that is one specification that I would want to know. Especially transmitting from the ocean surface. I’m just not sure that you are getting significant increase in discovery likelihood over SMB with mirror and whistle with 1 watt VHF on the ocean surface. Just to play Devils Advocate.

 

[KevinNM]

There are several PLB choices, but I am not finding many options for water/pressure proof canisters that are suitable for diving. By suitable for diving I mean ease of storage/carrying/attaching, etc.

It appears that the popular McMurdo Dive Canister is no longer available. I sent Star Marine Depot an email to see if they have any idea as to future availability and they have not responded.

Any recommendations? If you already have a custom rig can you please share?

Thanks!

Light monkey can and will build a custom canister. It’s cheaper it it’s one of the standard battery pack sizes. But still not cheap. Basically it’s the battery canister without a hole drilled in it.

If you need or want a different size they can do that, but will be more.

You need to call them to talk about this. Ideal solution is you send them all the stuff you want in the canister and they choose the smallest stock one they have that will do it.

Their stuff is really well made.

 

[Steelyeyes]

According to prophecy the Dive Alert can be heard up to a mile away. I suppose that's only downwind in a stiff breeze though. I've never had the guts to test mine. I'd like to keep what hearing I have.

 

[Dan]

So what is the transmit power for the VHF? Maybe I overlooked it, but that is one specification that I would want to know. Especially transmitting from the ocean surface. I’m just not sure that you are getting significant increase in discovery likelihood over SMB with mirror and whistle with 1 watt VHF on the ocean surface. Just to play Devils Advocate.

1 watt seems to be sufficient to transmit VHF signal 10-20 km away for PAB. PLB requires 5 watts to transmit 406 MHz as the LEOSAR is orbiting about 850 km above earth & GEOSAR is even further away, 35786 km away from earth.

You may want to ask those liveaboard companies why they use PAB, over PLB.

I do carry mirror, SMB, wistle too and use them whenever appropriate. The more options I have, the better change of me being found sooner.

 

[Dan]

According to prophecy the Dive Alert can be heard up to a mile away. I suppose that's only downwind in a stiff breeze though. I've never had the guts to test mine. I'd like to keep what hearing I have.

It's loud. I test mine with my head underwater during checkout dive. You need to test it once during a checkout dive. I'm on my 2nd Dive Alert now. The 1st one lasted for about 5 years.

 

[fsardone]

Hello there,
below my kit but mental preparedness is as important if not more than kit. My job was flying fast jet and I did a few survival training courses (sea mountain and escape). Having the right kit, knowing how to use it and its limitations (PAB vs PLB comes to mind) is important. The will to survive is way more important. I cannot convey the content of a survival course but the psycological aspect is more than the kit. In escape training we were deprived of all the kit. Here we are only discussing how to improve chance of being found. The importnat bit is ... survive of which being found is only a bit.
Custom solas sticker
DiveSigns.com: Reflective hard wearing vinyl stickers for all your diving needs..., Be Seen When It Counts
Canister
PLB DIVE CANISTER NOV2016 INC BELT MOUNT
PLB
https://www.amazon.co.uk/ACR-ResQli...y&sprefix=acr+resq,aps,227&sr=8-1-spons&psc=1

 

[Protondecay123]

1 watt seems to be sufficient to transmit VHF signal 10-20 km away for PAB. PLB requires 5 watts to transmit 406 MHz as the LEOSAR is orbiting about 850 km above earth & GEOSAR is even further away, 35786 km away from earth.

You may want to ask those liveaboard companies why they use PAB, over PLB.

I do carry mirror, SMB, wistle too and use them whenever appropriate. The more options I have, the better change of me being found sooner.

You may find this interesting to read. How far can I talk - Radio Range information

 

[CuzzA]

In my opinion a VHF radio is not a practical solution for a diver lost at sea situation. You would pretty much have to be able to see your vessel unless you're in dead flat calm conditions.

With the odds of being in a lost at sea situation fairly low, but still very much possible, I don't see the logic in carrying a VHF when you could carry a PLB. It's like bringing a .22 to hunt a bear.

For a little perspective, here's a decent read on the subject. If Nautilus is claiming 34 miles, I say bs.

https://www.boatingmag.com/marine-vhf-radio-range

Marine VHF Radio Range
The real deal on VHF marine radio range

By Kevin Falvey March 30, 2011

Ask 10 boaters about the range their marine VHF radio achieves and you’ll get 10 different answers. Just how far can you count on your distress call being heard?

Marine VHF Radio Range


Earth Is Round
Marine VHF radios operate between 156 and 172 MHz, a sliver of the very high frequency band of radio waves between 30 and 300 MHz. It’s FM radio. We know from taking trips in our cars that we have to change stations more frequently to get good reception when listening to FM (usually while a favorite song is playing).

Power output is often thought to increase range, but really, the difference in range between a 25-watt fixed marine VHF radio and a 5-watt handheld is due to the fixed mount’s antenna being taller, and therefore it can “see” farther. More power will allow you to punch through static and other radio traffic better, but only within the range dictated by antenna height. Marine VHF radios work on a line-of-sight basis. That is, they can transmit and receive to and from another antenna as long as that antenna is above the horizon. How far is that? Standing in the cockpit of a boat, the distance to the horizon for most adults is about three miles.

Can You Hear Me Now?
Mount an 8-foot antenna so that it’s 12 feet above sea level, and the horizon increases to about 4.5 miles. Of course, we’ve all communicated farther than that with a VHF radio. That’s because the height of the other antenna also comes into play.

Say your buddy has an antenna mounted atop his large cruiser at 18 feet above sea level. Combined with the 12-foot height of your antenna, the two of you could converse while about 6.7 miles apart. If the Coast Guard’s antenna is 100 feet tall, you can expect a reliable range of about 13 miles. Your buddy’s 18-foot antenna would net him a range of about 13.3 miles.

The actual distances are a bit farther, due to atmospheric refraction, but these are the distances you can count on, making satellite phones, EPIRBs (emergency position indicating radio beacons) and PLBs [(personal locator beacons)](personal locator beacons very wise for anyone cruising open waters. To see a chart of the Coast Guard’s VHF coverage in your area, visit navcen.uscg.gov.

​

Now, think about your tiny antenna on a handheld VHF, bobbing in 2-3's and the angle is all over the place as you try to talk into the mic, hoping someone has turned their VHF on, which most recreational boaters carelessly don't. Not to mention I believe the DSC feature was phased out on the Nautilus.

If someone invented a PLB w/ VHF, that would be nice, but given the option, buy the PLB.

​

 

[Protondecay123]

In my opinion a VHF radio is not a practical solution for a diver lost at sea situation. You would pretty much have to be able to see your vessel unless you're in dead flat calm conditions.

With the odds of being in a lost at sea situation fairly low, but still very much possible, I don't see the logic in carrying a VHF when you could carry a PLB. It's like bringing a .22 to hunt a bear.

For a little perspective, here's a decent read on the subject. If Nautilus is claiming 34 miles, I say bs.

https://www.boatingmag.com/marine-vhf-radio-range

Marine VHF Radio Range
The real deal on VHF marine radio range

By Kevin Falvey March 30, 2011

Ask 10 boaters about the range their marine VHF radio achieves and you’ll get 10 different answers. Just how far can you count on your distress call being heard?


View attachment 510721
Marine VHF Radio Range


Earth Is Round
Marine VHF radios operate between 156 and 172 MHz, a sliver of the very high frequency band of radio waves between 30 and 300 MHz. It’s FM radio. We know from taking trips in our cars that we have to change stations more frequently to get good reception when listening to FM (usually while a favorite song is playing).

Power output is often thought to increase range, but really, the difference in range between a 25-watt fixed marine VHF radio and a 5-watt handheld is due to the fixed mount’s antenna being taller, and therefore it can “see” farther. More power will allow you to punch through static and other radio traffic better, but only within the range dictated by antenna height. Marine VHF radios work on a line-of-sight basis. That is, they can transmit and receive to and from another antenna as long as that antenna is above the horizon. How far is that? Standing in the cockpit of a boat, the distance to the horizon for most adults is about three miles.

Can You Hear Me Now?
Mount an 8-foot antenna so that it’s 12 feet above sea level, and the horizon increases to about 4.5 miles. Of course, we’ve all communicated farther than that with a VHF radio. That’s because the height of the other antenna also comes into play.

Say your buddy has an antenna mounted atop his large cruiser at 18 feet above sea level. Combined with the 12-foot height of your antenna, the two of you could converse while about 6.7 miles apart. If the Coast Guard’s antenna is 100 feet tall, you can expect a reliable range of about 13 miles. Your buddy’s 18-foot antenna would net him a range of about 13.3 miles.

The actual distances are a bit farther, due to atmospheric refraction, but these are the distances you can count on, making satellite phones, EPIRBs (emergency position indicating radio beacons) and PLBs [(personal locator beacons)](personal locator beacons very wise for anyone cruising open waters. To see a chart of the Coast Guard’s VHF coverage in your area, visit navcen.uscg.gov.


View attachment 510722
​

Now, think about your tiny antenna on a handheld VHF, bobbing in 2-3's and the angle is all over the place as you try to talk into the mic, hoping someone has turned their VHF on, which most recreational boaters carelessly don't. Not to mention I believe the DSC feature was phased out on the Nautilus.

If someone invented a PLB w/ VHF, that would be nice, but given the option, buy the PLB.

​

Agree!