Rescue is just a push of a button away… or is it?


This is the first of a series of articles addressing aspects of sea kayak safety. Rather than imitate some of the excellent safety articles which have appeared previously in the club magazine (see box below) and in other kayaking publications, I thought telling anecdotal stories would provide both some light entertainment, as well as highlight lessons I have learned and help readers profit from others’ experiences without suffering the consequences.

I used to find the sight of a rescue helicopters quite exciting, but now they just make me nervous.

The familiar red and yellow Westpac Rescue chopper carved a tight orbit overhead, pounding my eardrums with the noise of its rotors. It was flying so low I thought I could smell the avgas in the downdraft and almost see the whites of the winchman’s eyes as he crouched in the doorway, looking sternly down at us.

With the crewman’s piercing stare and the throb of the rotors, an ominously familiar feeling of dread welled up in the pit of my stomach.

The last time I had seen this very same aircraft above me, I had, unknowingly, just paddled past two of my fellow paddlers who were literally smashed up on the rocks at the base of sheer cliffs near Eagle Rock in Royal National Park – and they had no Personal Locator Beacon (PLB). That was eighteen months ago and a mere ten kilometres to the south of where I was now.

How were they rescued without a PLB, in a place where there was no mobile coverage and where VHF radio was useless (high cliffs and no other vessels in range)? That’s another story for the next issue…

But right now the rescue chopper was obviously taking a close interest in our group of kayakers practicing deep water rescues as part of the club’s recent Sea Leader training course. A number of the group were out of their boats, so in spite of the benign conditions, we might have looked a little bit like we needed a rescue.

We did not of course, but I was concerned by the fact that, about an hour previously, my PLB had begun to emit the odd, intermittent, single beep.

After a few of these strange beeps (which were not like the sound the PLB makes when using the self-test function), I tried the self-test again. The beacon did not respond at all. It seemed to be totally lifeless. It did occur to me that the PLB might just possibly have been transmitting, but since it was apparently dead, had not been activated, the antenna was not deployed and the strobe not flashing, this seemed unlikely.

Not that long after hearing the beeps, I had also seen the Westpac rescue chopper flying around, but because it didn’t home in on us directly, I reinforced my conclusion that the PLB was not transmitting. If it was, the aircraft would have picked up and homed in on the local 121.5 MHz homing signal which the PLB also emits as well as the 406 MHz signal with GPS information.

I mentioned all this to Rob, who was instructing and who agreed that he didn’t think the beacon was transmitting. Nevertheless, just in case, we both switched our radios to Channel 16 to pick up any potential search and rescue traffic.

With the crewman still staring down at us, I waved my radio at the chopper circling overhead, in case they might call on Channel 16, but instead the aircraft did one more orbit and flew off.

A few minutes later I did get a call on Channel 16, but it turned out to be Sharon Betteridge. Sharon had been leading a trip at Bonnie Vale, a couple of kilometres from where we were now. “Guy? The Rescue Coordination Centre just phoned to say that your beacon is transmitting!”

However, the beacon still appeared to be dead. I called the helicopter on Channel 16 and advised them that I had just been made aware that my beacon had been activated, but we were not in need of a rescue, as the beacon appeared to have malfunctioned. The chopper acknowledged and went home for tea.

I found out later from a friend on duty at the time in AMSA’s Rescue Coordination Centre (RCC) that they had dispatched the rescue helicopter and water police to look for me in spite of the fact that they didn’t have any position information from the PLB. RCC had figured out the general location from my contacts registered on the AMSA 406 MHz Beacon database, and by checking the club website to make contact with committee members who might know exactly where the Sea Leader training was taking place.

In later conversations with RCC in Canberra, it turned out that the beacon had in fact transmitted on 406 MHz for about one minute. This was just enough time for the beacon signal to be registered in the RCC, but not enough time for the satellite to get a GPS fix. And because it had only been active for a short while, the beacon did not transmit a homing signal on 121.5 MHz, which is why the helicopter flew around looking for us rather than homing in on the beacon signal. In spite of the short transmission, RCC were still obliged to initiate a response.

The cause of this faulty transmission was, according to the manufacturer GME, self-activation due to water ingress into the PLB.

The beacon was only two years old, in excellent condition, and I had used the self-test function satisfactorily only a couple of weeks previously. Nevertheless, as others have experienced with GME MT410/MT410G beacons, water ingress led to failure of the beacon, or in this case, self-activation.

There have been other reported instances of GME PLBs failing. Stuart Trueman had two fail on his trip around Australia, and ‘Gnarlydog’ has also reported this issue on his blog.

I questioned this with GME, who said that the beacon is rated as waterproof. However, the GME product manager for the MT410/MT410G also told me that rubber seals do tend to perish over time and water ingress can occur, particularly where a beacon is subjected to heating and cooling. When exposed to heat, air inside the unit expands, but then if it is suddenly cooled (for example, being left in the hot sun at lunchtime, followed by being doused by a cool wave on launching) the air inside the unit quickly contracts, forming a partial vacuum and sucking moisture in.

GME’s website says the MT410G has a “sealed waterproof design” and specifies that waterproof means “submersion to 1 metre – exceeds IP67 standard”. A cynic might observe that they have been careful not to claim that the MT410/MT410G is waterproof.

I haven’t shelled out $70 for the Australian Standard 4280.2 which sets out the environmental and durability standards for PLBs (EPIRBs are subject to Australia/New Zealand Standard 4280.1) but I understand that PLBs have to transmit for 24 hours and need to be waterproof to IP7 standard. EPIRBs meanwhile have to transmit for 48 hours, and be completely waterproof for use in water (probably IP8 standard).

According to Wikipedia, IP7 means the unit has passed a waterproof test which involves being immersed to 1 metre for 30 minutes. GME told me that out of the “tens of thousands” of units which they have manufactured, they have had “very few” which fail. The product manager would not say exactly how many. Every GME beacon is also subject to waterproof testing before it leaves the factory.

The GME product manager also told me that their PLBs are manufactured with a sachet of silica gel inside the unit to absorb any moisture that does make its way in. The implication is that GME expects some degree of moisture ingress, albeit a small amount.

So is the IP7 standard sufficient for kayaking purposes? It’s worth noting that neither the A/NZ Standard nor PLB manufacturers appear to have considered the specific requirements for and potential use by sea kayakers: it may be a trivial point, but while PLB product brochures show plenty of images of sailors, skiers, walkers and aviators, none of them contain images of kayakers.

The relevant authorities expect most vessels to carry an EPIRB if more than 2nm offshore. NSW Maritime regulations are clear on the fact that carriage of a PLB does not satisfy the requirement to carry an EPIRB (i.e. if you are more than 2nm offshore) although they do state in the ‘Modified Requirements’ section of the Boating Handbook that “Canoes/kayaks are exempt from carrying safety equipment on all waters, but hand-held marine radio or mobile phone in waterproof pouch strongly recommended.”

Commonsense dictates that if kayakers are going to paddle into an environment where we cannot guarantee self-rescue or cannot contact an external agency by radio or phone, a PLB should be carried, particularly as EPIRBs are too bulky for carriage on the person.

Regardless of the detailed design limitations, most of us see the word ‘waterproof’ on the box of a PLB and consider that is probably sufficient for our purposes. Anyway we don’t have much choice as PLBs are not yet manufactured to higher standards.

Practical experience also suggests that current waterproofing standards for PLBs may be adequate to some degree. My previous 121.5 MHz beacon had survived OK for five years under the same conditions, living in its neoprene pouch in the front pocket of my PFD, and being subjected to any amount of rolling and a good number of big wave hits and hefty trashings both in the ocean and on white water rivers.

However, in spite of the fact that my old beacon seemed to cope with the rigours of day to day kayaking, it’s worth noting that the dynamic pressure generated by a big wave hit could, even though the PLB is in a pouch inside a PFD pocket, potentially be substantially greater than the IP7 standard.

However, mine and others’ recent experience of beacon failures suggests that IP7 may not in fact be sufficient for sea kayakers’ purposes. It is not hard to conclude that in an emergency the IP7 standard might be inadequate, and your PLB might stop transmitting.

Should PLBs be totally waterproof as the A/NZ Standard specifies for EPIRBs? It is reasonable to suggest that they should, because if immersion during an emergency exceeds the current standard they may not be able transmit for the required 24 hours.

However, the fact is that PLBs currently only have to comply with the existing A/NZ standard.
So we as sea kayakers need to be aware that the current A/NZ standard for PLBs may not necessarily be sufficient for our purposes, as well as think about lobbying for changes to that standard.

More to the point, when considering PLB reliability, it has to be borne in mind that, like any piece of electronic equipment, if it is exposed to conditions which exceed the A/NZ standard or manufacturer’s stated level of waterproofing, a PLB can potentially fail. According to AMSA, beacon malfunction is a growing issue, with around 200,000 PLBs now registered in Australia.

With that number of PLBs in circulation, it is inevitable that a small percentage of these, regardless of brand, will probably malfunction in some way. It is perhaps unrealistic to expect any piece of electronic equipment to survive in a saltwater environment over the long term without additional protection.

This issue may not be peculiar to the GME MT410/MT410G. It may just be that it is because they may be among the most popular model of PLB with sea kayakers and have been subject to more demanding environments. I would be interested to hear of any issues with GME or other brands of PLB of which club members may be aware.

Nevertheless, until the A/NZ standards are changed to require a higher level of waterproofing for PLBs, for all practical purposes a PLB seems to be the only realistic option for a sea kayaker to carry as an emergency beacon on their person. So, bearing the limitations of the current standard for PLBs in mind, paddlers should:

  • be aware of the specified design standards of your PLB – and particularly try and avoid excessive heating and rapid cooling of the unit: e.g. don’t leave it in full sun during a lunch stop;
  • check your PLB for any potentially visible damage to the casing and test it regularly (within the battery life limits indicated in the manual);
  • consider further waterproofing measures (e.g. tape the seams, put silicon in screw recesses and/or keep your PLB inside a waterproof pouch for added protection, but remember it must be easily accessible in an emergency and it should remain tethered to you); and
  • if you do have the misfortune to hear your unit beeping, know how to deactivate the unit (read the manual), and advise the Rescue Coordination Centre on 1800 641 792.

Just as important as caring for your PLB is ensuring that you carry it on every trip. In the next article, I’ll describe that day when carrying a PLB would have been really, really useful for a couple of paddlers…
Box 1: Useful NSW Sea Kayaker safety and lessons-learned articles:
Just How Much Safety Equipment Is Really Appropriate To Carry? [Wayne Langmaid, 2000, Issue 41]
‘Trip Leaders’ Responsibility’ [Ross Winter, 1998, Issue 35]
‘Safety Review: Incident at Cons Cleft, Broughton Island’ [2010, Issue 77/78]
‘X Bass Strait S’Easy as AB…D’ [Andrew Watkinson’, 2003, Issue 52]