Combined PLB and AIS beacon

[rogerthebodger]

OK so we know that AIS works on VHF channels 87 and 88 where as DSC works on channel 70.

But are the messages the same or are there differences.

I have both AIS ans DSC radio connected to OpenCPN and know that I can get a distress messages from both and have tested my DSC using position requests.

Any one know of a way to test DSC emergency without setting off a general emergency by pressing the red button.

Yes I know I could setup a PC and program messages but that's sounds like too much work.

Like EPIRB's most of these systems do not include a proper legal end to end procedures to test emergency calls.

 

[dom]

I would say that's then a combined AIS and DSC beacon.

COSPAS-SARSAT, AIS, and VHF DSC are three independent systems. There are various combination transmitters available (plus at least one that also does VHF voice with a recorded message!) but the technologies are still separate concepts. I'm always a bit bemused at how many people (not you ) seem to mix up and conflate them with each other.

Pete

No that's a fair point: they're all different and for example I don't think that the McMurdo S20 has the AIS/DSC combination. What I like about such sets though is that they will blast out a DSC alert on the radio regardless of how the AIS alarm is setup.

Speaking of DSC alarms, the biggest irritation in the Channel at night is Joburg Traffic endlessly activating the DSC alarm:

"Appelannt tous, appelant tous, appelant ....this is Joburg Traffic, Joburg Traffic ...will the ship proceeding at blah blah blah ...please take your pizza out of the oven!"

Solent and Portland seem much less shouty.

Edit: apols in advance for the drift

 

[Millie Skipper]

Perhaps I'm being stupid here but I don't get the fascination of these combined units.

I for example have an Ocean Signal AIS attached to the air filling tube on my lifejackets; it's as small as the emergency light and nobody would ever guess it was there. I also have a PLB fitted to the same jackets and that's slightly bigger.

Is the immeasurably small convenience advantage of a combined unit not outweighed by a potentially bigger reliability advantage in being sure that at least one will work? Unless I suppose the combined unit comes in way cheaper.

I have both AIS and PLBs. I can see that having a combined unit seems convenient and compact but I think that having an automatically triggered AIS beacon that aids recovery by the crew on my boat or those nearby without initially activating a PLB to alert the rescue services is beneficial. The PLB can then be activated after a short time if no recovery by a local vessel has been made.

 

[dom]

I have both AIS and PLBs. I can see that having a combined unit seems convenient and compact but I think that having an automatically triggered AIS beacon that aids recovery by the crew on my boat or those nearby without initially activating a PLB to alert the rescue services is beneficial. The PLB can then be activated after a short time if no recovery by a local vessel has been made.

Hi Millie and welcome on here!

 

[bitbaltic]

having an automatically triggered AIS beacon that aids recovery by the crew on my boat or those nearby without initially activating a PLB to alert the rescue services is beneficial.

PLBs aren't automatic so it would kind of have to work that way regardless of whether it's beneficial or not.

 

[Otter]

My apologies to the earlier poster, I didn't know dual AIS/DSC units were available.

 

[mm42]

An all in one AIS/DSC/PLB would be ideal, the AIS and DSC being triggered upon lifejacket activation, the PLB being switchable.

Till then I've an AIS unit (McMurdo Smartfind) on the inflation tube of my LJ and a Fastfind in the pocket of my LJ.

 

[dom]

You must have huge emergency lights. Apparently the MOB1 is nearly 14cm long.

I looked into doing the same as we have FastFind 220 PLBs inside all our LJs but along with a sprayhood and light on one side (bayonet fitting and bottle on the other) there was no space even for the MOB1, which is why I'd be interested in a combined unit which I guess won't be much bigger than the PLB. Where are you stowing your PLB, inside or outside the jacket? we found them inconvenient when stowed on the harness, and in discussions with a pal who is also DLA/sea safety officer at the local station, concluded they'd probably be inaccessible when overboard anyway, which is why they are inside the jacket.

I am considering putting an AIS beacon inside our son's LJ instead of the PLB, because even though he's 10 now I wouldn't trust him to fire a PLB and the AIS beacon is automatic. If he fell overboard it would a) allow us to report his position to the emergency services and b) stand a good chance of recovering him ourselves.

Very funny Yes the Ocean Signal AIS beacon is indeed about 13.5cm length, but the width dimension relates to the wide bit on top. The main body is as skinny/skinnier than the inflation cartridge and is pretty unobtrusive. It will also automatically activate upon inflation whereupon it will send a DSC alert to mother ship and start to transmit an AIS MOB beacon. I'd definitely recommend it for kids -- but remember the auto-activation will only work if with a canister inflated LJ and not with a foam or a foam/manually-inflatable ones. The child will however need to know to keep the aerial out of the water and approx vertical.

The PLB I usually only fit further offshore and as you say these should definitely be fitted to the LJ: mine are on an inside pocket, but an outside one is prob fine too. As you say the belt system is hopeless: out of sight when the LJ inflates and flailing around bashing against everything when the LJ is being taken on/off, left swinging around in the heads, or whatever.

 

[bitbaltic]

Very funny Yes the Ocean Signal AIS beacon is indeed about 13.5cm length, but the width dimension relates to the wide bit on top. The main body is as skinny/skinnier than the inflation cartridge and is pretty unobtrusive. It will also automatically activate upon inflation whereupon it will send a DSC alert to mother ship and start to transmit an AIS MOB beacon. I'd definitely recommend it for kids -- but remember the auto-activation will only work if with a canister inflated LJ and not with a foam or a foam/manually-inflatable ones. The child will however need to know to keep the aerial out of the water and approx vertical.

The PLB I usually only fit further offshore and as you say these should definitely be fitted to the LJ: mine are on an inside pocket, but an outside one is prob fine too. As you say the belt system is hopeless: out of sight when the LJ inflates and flailing around bashing against everything when the LJ is being taken on/off, left swinging around in the heads, or whatever.

Excellent thanks for the info. Yes all our jackets are automatic, I realise the beacon needs to pull a cover off (or equivalent) on inflation. I will take another look at the MOB1. Of course if I buy one for our lad I can always see if it will pack in somehow with the PLB in the other jackets. I think he'd manage to hold something up out of the water as needed for the AIS, but with the PLB I'm sure he'd be bobbing about with a confused look on his face wrangling with a bit of yellow plastic!

Cheers

 

[Gwylan]

There is an implied thought that there is someone left on board who understands what the alarm means, can interpret the information on the plotter and or VHF and can sail the boat back to find you.

I do not always have that much confidence in some crews.

So I think, pending an improvement in the skill base of crew that I recruit, I shall stick with putting my trust in the wonderful people at Falmouth to extract me from the do-do.

 

[grumpy_o_g]

Anyone got any news on the UK and few other countries finally fixing the bizarre radio regs that mean devices like the MOB1 can signal an AIS alert to all ships but not a VHF DSC alert? Currently at the moment at least the DSC alert can only go to the mother ship which I believe is the MMSI code you programme into the MOB1. That makes it pretty useless for much of the time if you regularly sail on more than one vessel.

 

[KellysEye]

We sailed over 10,000nms with no PLB's the point is not to go overboard. Jackstays, a U bolt in the cockpit and harness with one long and one short tether. We always clipped on at night and bad weather. We were sailing upwind and up current off the Portuguese coast with large waves and swell in 25 knots and daylight. We were taking lots of water over the boat and it washed the inflatable danbuoy off our starboard quarter it disappeared in four minutes, bear in mind a danbuoy is much higher than a head. The chance of turning around and finding one of us was nil. We were clipped on.