Arwen's meanderings

Hi everyone and welcome to my dinghy cruising blog about my John Welsford designed 'navigator' named Arwen. Built over three years, Arwen was launched in August 2007. She is a standing lug yawl 14' 6" in length. This blog records our dinghy cruising voyages together around the coastal waters of SW England.
Arwen has an associated YouTube channel so visit to find our most recent cruises and click subscribe.
On this blog you will find posts about dinghy cruising locations, accounts of our voyages, maintenance tips and 'How to's' ranging from rigging standing lug sails and building galley boxes to using 'anchor buddies' and creating 'pilotage notes'. I hope you find something that inspires you to get out on the water in your boat. Drop us a comment and happy sailing.
Steve and Arwen

Wednesday 25 March 2020

Is it time to get a new PLB?

I recently posted a question on the Dinghy Cruising Association Facebook forum page.

“Afternoon fellow DCA’ers.......remembering there is no such thing as a dumb question.....and you don't know what you don't any of you dinghy cruisers (particularly here in UK) carry some form of Personal Locator Beacon or personal emergency radio device of some form (other than VHF radio)? If so, what do any of you carry on your person or recommend? Or is a handheld VHF, mobile phone and flares enough? By the way my handheld VHF doesn't have a DSC button”

Of course, I wrote this before all the lockdowns and enormity of our changing lifestyles here in the UK – when I was dreaming of sailing down to Falmouth via Fowey and Lostwithiel; calling back in Mevagissey and so on. Ah well, maybe next year.

Anyway, seventy odd comments later – Roger Barnes, the President of the DCA and I have concluded that perhaps my question wasn’t as stupid as it might have first appeared!

So below I share what I have learned from internet research and Facebook Dinghy Cruising forum members. I cannot guarantee that all this information is accurate so it may need further checking.

Starting at the beginning - when I am sailing Arwen, clipped to my jacket or in an under-armpit lifejacket belt bag or within the pockets of my Kaikoura Expedition PFD if I happen to be wearing that, I carry the following items:

·       SPOT PLB
·       Safety knife
·       Mobile phone
·       Waterproof, floating handheld ICOM VHF (not DSC enabled)
·       Flashing lifejacket laser light
·       Safety mirror and whistle
·       Hand held Garmin etrex GPS
·       Lip salve and tiny 30ml sun cream bottle

My SPOT PLB device, a subscription model, takes about 20 seconds to get a satellite fix using a combination of globalstar and GEOS satellite networks. It has several useful features from sending ‘check-in’ texts to family to an SOS emergency call for help button and ‘tracking’ feature. Its particularly useful when creek crawling far inland on tidal rivers in steep sided river valleys where there is no mobile phone signal as I can ping an ‘I’m OK’ message to the ‘boss’ just before going to bed reassures her that I’m still alive. Further details can be found at

So, why am I thinking about carrying an additional personal emergency beacon of some form? 

Well, firstly SPOT is a subscription service – and that adds up over the years. Secondly, it takes around 20 seconds to get a satellite lock, the face of the unit has to be facing skywards and the SOS goes to an emergency rescue co-ordination centre in the US which then contacts the UK Falmouth Coastguard rescue centre or the UK Police – depending on whether the SOS is coming from the sea or land. That’s quite a delay factor Whilst I’m floating around in the sea, adrift, waiting for people to contact others to then alert rescue services here in the UK! Although it is claimed it is fully waterproof and can be submerged – I’m not truly convinced about that either!

Well you can see the issues. So,maybe it is time for something more ‘immediate’.

There are lots of devices out there and I guess it depends what kind of sailing you do.  For me, I do lots of creek crawling up my local tidal rivers and then the occasional jaunt inshore along the coastline – up to four nautical miles off shore. Most of my day trips are done within Plymouth Sound or up the River Tamar and there is normally some boat traffic around – Navy boats, MOD police, tourist boats, local inshore fishermen, recreational yachts and various small foot ferries shooting between various quaysides.

So, what’s available if I want to get a new personal emergency radio device for next year?

One set of devices are basic ‘alerting technology’ – they alert others that you are in distress but may not update rescuers about your location. These would be things like VHF DSC – sending distress messages to your own boat and nearby boats using an inbuilt Global Navigation satellite system (GNSS). The message gets repeated and only stops when acknowledged. Locating technology is needed by rescuers to help locate you and there are transmission limitations to VHF, especially if you are in water with waves which can block signals. (Basically, it is a line of sight technology). VHF DSC is monitored by the UK Coastguard and all SOLAS vessels.

Then there are devices which use 406 MHz Cospas-Sarsat – which send distress signals through the Cospas-Sarsat satellite system to a rescue co-ordination centre. If you get such a device, ensure it has GNSS technology, for without it, it can take up to two hours to achieve a position with an accuracy of 5km apparently!  Such devices have to be registered with the UK Coastguard. Having transmitted the alert these devices then continue to transmit updated positional data (remember GNSS is far more accurate at this) to the Rescue co-ordination centre which then forwards it to any rescue craft. One thing to note about 406 MHz Cospas-Sarsat technology is that it will not necessarily alert nearby boats to your distress.  

There are EPIRBs (Emergency Position Indicating Radio Beacon) which are registered to your vessel. Some also use 121.5 MHz homing beacons as well and newer ones will also have AIS (see below for further details) which will send AIS messages to any AIS equipped vessels in your vicinity – which speeds up your rescue chances. 

Then there are some 406 MHz PLB’s (Personal Locator Beacons). Used in life or death emergency situations to alert SAR to your location, new ones are accurate down to 100m. Many of the newer models also have the 121.5 MHz homing beacon as well. PLBs are programmed to individuals and have to be registered with the local authority rescue coordination services. I would also advise making sure that your PLB of choice is either IPX7 – waterproof up to 3’ of water or more ideally IPX8 – waterproof in more than 3’ of water.
After ‘alerting technology’ there is then ‘locating technology’ which helps rescuers find you. Remember though, it doesn’t alert then to your distress in the first place.  Some devices use AIS (automatic identification system) which broadcasts your location to all vessels fitted with AIS receivers within VHF range (up to 5 miles range to all SOLAS vessels, UK rescue helicopters and lifeboats). AIS will update your locational position regularly on AIS enabled chart plotters etc. They are often marketed as MOB devices and are designed to fit inside life jackets and to activate immediately on inflation.
Some locating devices (as indicated above) use 121.5MHz homing signals which again can be picked up by Coastguard helicopters and lifeboats using directional finding equipment to track the signal. However, most other vessels don’t have this direction-finding technology on board.

Which now leads to the $6 million question – what would be best for my sailing circumstances?
The Maritime and Coastguard Agency suggest that if you sail close to the shore where there are likely to be other boats nearby with receivers then you’d benefit most from a local device which alerts other nearby vessels to your distress and if the Coastguard receive the distress message they will try to locate nearby vessels in a position to assist you (so devices like a DSC VHF radio, DSC enabled chart plotter, a MOB device or AIS).
However, I also go up to four miles offshore on forays west or east along my coastline sometimes sailing up to thirty miles in a day. I don’t always see another boat for a few hours at a time, especially if I am sailing on a week day outside of the holiday periods (the privilege of being retired). As a lone sailor as well, then the MCA argue I’d benefit from using a device with Cospas – Sarsat 406 satellite technology – so a PLB or EPIRB may be more appropriate.

It is all rather confusing, or perhaps its just me. Hence my question to the Dinghy Cruising Facebook Forum.

The responses were, as always very interesting and fell into a small number of categories

        1. Carry VHF (DSC), mobile phone and flares (DSC has faster response time if other boats around)
2.      Carry VHF DSC and mobile phone – not flares – too dangerous. (Have phone in waterproof case)
3.      Carry VHF radio (DSC or not), mobile phone and PLB with 406 technology – preferably non subscription (and that can be used on land-based activities worldwide as well)
4.      Carry VHF DSC radio, PLB, smokes, flares, whistle. (No mobile phone as it can be unreliable in isolated areas like Scottish Islands or under high cliff line).
5.      2 x VHF DSC, mobile phone, smokes and flares, and full EPIRB attached to boat (because swimming and trying to hold a PLB in correct orientation in a wavy sea could be very difficult. Losing contact with the boat would result in you dying before rescue services got to you in most cases; things hanging off PFD’s can hamper you getting back into a swamped righted boat and having a EPIRB attached to the boat would remind you to stay with the boat even if it was lying on its side, using it as a life raft. They also float free on a cord attached to the boat in the correct orientation, allowing you to get on with sorting out the boat).
6.      Carry only orange smokes and a VHF radio

PLB’s mentioned included ‘RescueMe’, Garmin ‘Inreach mini’, ACR, Kannad Marine SafeLink Solo.  The main advantages of non- subscription PLB’s were seen as their use in other activities, cheaper in the long run than renewing flares every three years (with their added fire hazard and disposal problems) and having something on you should you get separated from your boat. Many who commented reminded others that it was important to be really familiar with how to activate and orientate your chosen PLB. Major disadvantages of some PLBs is that they don’t work under water – so it must be high up on your shoulder; and of course, you have to deploy the antenna – which is difficult to do if you are unconscious or hypothermic. In addition, when battery life is met – it has to be returned to manufacturer for replacement battery and if you accidently send an SOS you can’t cancel it immediately.

Some forum members commented about dangers of carrying flares and there was some discussion as to whether it would be better to switch over to electronic flares once your pyrotechnic flares had expired – although keeping the orange smokes – seemed a good idea for day time rescue location.
Finally, one commentator gave the anecdote that in South Australia it is the law that all vessels more than 3Nm from the shore must carry an EPIRB 406MHz; PLB’s are not approved but may be carried in addition to the EPIRB.

So, its decision time – stay as I am, get an EPRIB or a new PLB with 406 MHz Cospas-Sarsat technology or go for an AIS MOB device.

First of all, lets recap over the differences between a PLB and an EPIRB.

·       PLBs are registered to an individual whilst EPIRBs are registered to a vessel.
·       PLBs are good for those who do multiple land and water-based activities; EPIRBs are normally only used on boats.
·       PLBs require manual activation by the individual whilst the EPIRB can be manual or automatic activation but only on submergence. 
·       PLBs will transmit for a minimum of around 24 hrs continuously whilst an EPIRB normally transmits for at last 48 hrs.
·       Finally, not all PLBs float – an EPIRB definitely does!

PLB or AIS MOB device?

No contest I think – AIS is for MOB rescue in areas where there are plenty of boats; a PLB alerts emergency services to a life or death situation anywhere!

I’m leaning towards another PLB and am looking at the ones below:

ACR PLB 375 REsQLink+ 406 Buoyant Personal Locator Beacon


·       Flip up flap and turn on
F     Floats Easy registration and no subscription
Use in any country
If you use it in a real emergency ACR will give you a free replacement if you share your rescue story with them
To consider:
·       Battery has to be professionally replaced by authorized dealer
·       Larger than some of the other PLBs available

There is another version – the ACR PLB 375. This one is very light, fits in your hand, comes with a case, is waterproof but is based on a paid subscription model and as a major drawback – doesn’t float! Although no longer manufactured – you can still get them from various suppliers.
There is also the ACR PLB Aqualink. Again no longer manufactured, you can still get these units. It has a digital display and a battery certified for around six years from date of manufacture. Waterproof to around 10m for ten minutes, it has a typical battery life of around 30hrs when in use; 406 MHz with GPS with the 121.5MHz homing beacon and it floats.

 The McMurdo Fast Find 220

·       Fast and simple set up
·       Easy to use – extend the antenna and push the button
·       No subscription
·       Linked directly to rescue coordination centre
·       Can bring rescuers to within 60m of your location - has a 121.5Mhz homing beacon
·       Long battery life
·       Lightweight and compact
·       Has strobe light
·       Floatation pouch included and waterproof down to 10m

To consider:

·       Doesn’t send out ‘ok’ type messages like some PLBs
·       Doesn’t float and some have reported the cap is difficult to remove in an emergency

Ocean Signal RescueMe also known as PLB1


·       Seemed a popular choice amongst many dinghy cruisers who responded to my question
·       Very small and compact
·       Lightweight
·       Can be stowed in life jacket
·       No subscription required
·       Long battery life – last 7 years – will transmit 24 hrs plus
·       Floats in its pouch
·       Has a strobe light
·       Easy to use – deploy antenna and hit the on switch

To Consider

Haven’t found anything thus far

If you have a PLB which you would recommend, please do get in touch. In the meantime, in the difficult circumstances we all face wherever we are in the world, please, please take care, stay safe and stay in touch.  

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