PLB Verses Hand held DSC radio

[prv]

The best MOB device for non-remote waters is an AIS MOB beacon.

The makers claim a six-mile maximum range - paradoxically only if there are reasonable-sized waves as they're assuming you'll transmit as you go over the top of one. I wouldn't call the central English Channel "remote", but most of the time you're not within six miles of another vessel. Great for letting your own boat get back to you, or an alerted rescuer home in on you, but I wouldn't rely on AIS to alert a third party outside of very busy areas like the Solent. The manufacturers agree.

It does not require a voice conversation to explain the nature of the distress as DSC does.

Yep - although the benefit of a voice mayday is that it will engage all but the most determined luddite on the water. Think of all the derpy old men on this forum who've said they turn their radios off if the DSC alarm goes off because they don't understand how to silence it and can't read the details without their specs anyway. I've no evidence, but I suspect a lot of inshore fishermen are no better. Strange beeps and flashes are impersonal and ignored by some, but very few would ignore a human voice calling for help.

Pete

 

[bedouin]

Terrifying.

The best MOB device for non-remote waters is an AIS MOB beacon. That alerts vessels close enough to help you and requires little to nothing (if it's rigged to trigger with your life jacket) to operate it. It does not require a voice conversation to explain the nature of the distress as DSC does.

PLB is the best device for remote waters, but you have to operate it -- you have to deploy the antenna, trigger it, and hold it up above the water with the antenna directed in the right way. Could be hard in a storm, cold hands, etc.

VHF handheld is great because you can talk to someone, but very short range, and you have to operate it. I don't carry one of these on my person because limited usefulness and present models are very bulky. I would start carrying one if they ever make a really compact one for emergency use, with a long life single use lithium battery.

I do keep both a PLB and an AIS MOB beacon lanyarded in my life jacket.

A bit confused. AIS is VHF and so the range of an AIS beacon is no better than a VHF handheld - probably worse because the HH will transmit on higher power

Also I am not sure whether the signal from an AIS beacon will trigger an alarm on board a receiving vessel the way DSC will.

AIS is ideal on well crewed boats where you expect the crew to come back and pick you up - but for single/short handed sailing (which is what I do mostly) I am less convinced.

 

[Roberto]

FWIW, a number of boats here tested the AIS MOB beacon positioned at water level, it became barely visible at a couple of miles, even from boats whose AIS receiving antennas were at the masthead.

It is instead heavily endorsed (of course as well as epirbs, plbs etc) by the local AirForce SAR people, they cover most NE Atlantic, Biscay etc; they said their instruments can spot it at about 8-10 miles. For info, they have a lot of experience in dealing with non-Solas equipment, they are routinely sent to rescue the various accidents with ocean racing boats.

 

[BlackPig]

There was a case last year when an experienced singlehanded sailor ended up in the water alongside his boat. He had both Vhf and Plb but by the time he realised he could not save himself his hands were too cold to operate his devices!

Www.solocoastalsailing.co.uk

If he is clipped on and reaches the water he is doing it wrong. Have the lines in the middle of the boat and if any more than your legs go over the side shorten the harness. Double it over the lines if you do not have a short tether.

I carry PLB at all times when out of the cabin.

 

[prv]

Also I am not sure whether the signal from an AIS beacon will trigger an alarm on board a receiving vessel the way DSC will.

Depends on the receiving kit. It will trigger an alarm on mine, but on plenty of others it won't.

Pete

 

[KellysEye]

When we were long distance sailing the chances of getting one us of back on board in bad weather was nil, the same for a single hander. We fitted jackstays and had harnesses with one long and one short tether and always clipped on at night and in bad weather. The short tether stops you going over the rails and if going forward to the mast to reef I would clip on the short tether and go forward on my knees, at the mast I would clip on the long tether.

Because of that we didn't carry PLB's but did carry an EPIRB plus we had SAT C and a Satphone where the the emergency call takes a few minutes rather than the PLB/EPIRB satellites that can take an hour to pick up the signal. For coastal sailing a DSC radio would be quicker than a PLB for the reason mentioned.