Ocean Safety MOB1

[Graham_Wright]

As we generally sail as a couple, I have developed an extreme fear of MOB situations.
We each have a MOB1 and, in theory, if one of us goes overboard, the other should at least be able to locate.
MOB1s have a self test facility and, sure enough the little green light says " I am working".
However, the radio does not react to the alleged transmission. I know the MMSI numbers in the radio and the MOB1 are correct.
The test was carried out below deck. Is it possible the signal from the MOB1 without its tape antenna deployed was insufficient to reach the masthead?
Ocean Safety advise that the number of tests should be minimised to preserve battery power.

 

[Martin_J]

The manual suggests there is a separate test for a DSC Transmission test...

From that, I'd assume the "functional test" doesn't actually send an AIS Man Overboard alert but that the DSC Transmission Test does.

 

[Martin_J]

Correction...

Although the manual doesn't make it clear what each test does, the online product FAQ does.

MOB1 - Ocean Signal



Edit : added link to FAQ and I think the manual does make it clear if after page 13 I had read page 14!

Looks like i need to test all mine...

 

[Martin_J]

And to save me searching for the test instructions later....




I'll try out both tests tomorrow and see if the VHF does receive the DSC transmission and that the chart plotters all see the AIS MOB test transmission in the other test.

Thank you for prompting me to test.

 

[Martin_J]

And thinking about test location, if you're 50ft away and directly below a masthead antenna, it might not be the best place to test from... but I'll also give it a go tomorrow!

 

[Martin_J]

All three tests just done and they worked as per the manual.

I did the DSC test sitting at the chart table so 50ft under the masthead VHF antenna.. DSC alert was received immediately.

I'll try and put up short video of all three tests later if you like.

One thing I noticed was that the AIS position did appear on the chart plotter but was just a position during the test. Maybe I didn't leave the video running long enough to see a test message, but I do know from experience that in a real MOB situation, the B&G zeus does add the MOB message to the position indicator (although maybe that's from the DSC message).

 

[Martin_J]

MOB1 Functional test
MOB1 Functional test quick video

 

[Martin_J]

MOB1 DSC test performed from chart table, about 50ft below the masthead VHF antenna..

MOB1 DSC test

MOB1 AIS test performed in the cockpit (as per instructions to allow clear view of the sky) and MOB test indication shown on chart plotter.

MOB1 AIS Transmission test

 

[Martin_J]

The last test, the AIS test, does show on the chart plotter as an MOB AIS SART with the description MOB TEST...

 

[Graham_Wright]

Was the MOB1 antenna unfurled?
Having watched the video - Not!
Very informative response and greatly reflects the power of the forum.
Thanks.

 

[Martin_J]

I didn't unfurl the antenna for any of the tests.

The DSC test was, like your test, done at the chart table and the DSC message was received via the masthead VHF antenna.

I did then try the AIS test on one MOB1 at the chart table and on another at the helm..

The test at the chart table did get a GPS fix and the MOB showed on the plotter but was about 50metres out of position.

The test done at the helm, (as you can see in the video) showed the position as being right next to the boat.

Bearing in mind the instructions do say the AIS test needs to be done with a clear view of the sky, this was expected.

 

[dolabriform]

Thank you for posting this, I'm going to test all of ours

 

[Helidan]

I've never tested a MOB1 but regularly test the Kannad Safelink Solo often found in the Mullion Compact 150 lifejackets issued to the fishing fleet. The two tests are battery level and GPS receiver test to be carried out in clear view of the sky. The MOB1 in many respects is a better product in as far as most vessels can receive the transmission.

 

[Graham_Wright]

I tried again with mine without success. Clear view of the sky and the masthead antenna with MOB1 antenna furled and unfurled. I wondered how long it takes the eMOB1 to establish a GPS fix but I believe the flashing indicators did indicate a successful fix.
The suspicion lies now with the radio an old but very comprehensive Standard Horizon.
I need to find someone to send me a DSC transmission and check for success. I wonder if the coastguard (or NCI) could oblige.
I am sure the radio is properly programmed as I took immense care (only two attempts permitted before "return to the manufacturer").

 

[Martin_J]

Whereabouts is your boat based? There maybe sbdy nearby who can try. I guess you don't have a handheld VHF with DSC which you can do a position request or DSC call to.

Have you double checked your programming of the MOB1 itself?

Remember that the MOB1 does need to be programmed (with that flashing on screen program) with your main vessels DSC MMSI for the MOB1 to be able to send the alert to your specific on board VHF.

The video I took (and the instructions above) show that the DSC test does not include any requirement for a GPS fix.

It's only the AIS test that waits for the GPS fix before sending the AIS MOB TEST distress message.

 

[Martin_J]

Not so important but it is also worth nothing that there is a difference in the transmission timing of DSC messages in the event of a real MOB situation..



https://oceansignal.com/wordpress/wp-content/uploads/MOB1_DSC_Functionality.pdf

 

[Graham_Wright]

My hand held is an Icon M35 which, I believe, does not have DSC capability. (It is U/S at the moment as the charger has failed).
I will check the MOB1 programming but I did take care. I expect the code will be visible as a check.

 

[Martin_J]

You can't check what MMSI was programmed into the MOB1..

You can either clear the MMSI or re-program it. The Web based programmer seems easy to use.. You'll ideally need the rubber programming cover that comes with the MOB1 though.

 

[Graham_Wright]

I have emailed NCI to ask if they are able to check DSC functionality. From personal contact, I am aware they welcome traffic for radio checks especially. It presumably helps with training.

 

[jane.peckham]

Further to Martin’s original post I have a problem with MOB1 testing. We have Zeus2 and B&G V50 radio circa 2016.
We have 5xMOB1s onboard. 3 of them trigger DSC when tested. The other 2 work for AIS but not for DSC. Does anyone have any suggestions please? The MMSI must be correct for the AIS test to work.
Thanks in anticipation!