In the "Sailors confess" series, we confess our stupidest sailing mistakes. But we are also keen to hear your confessions. Send us your text, if possible with pictures, to mail@yacht.dekeyword "sailor's confession". If desired, publication will be anonymised.
Safe is safe
Testing safety equipment is a tricky business. On the one hand, you want to test the equipment as practically as possible, but on the other hand you don't want anyone to get hurt and of course you don't want to trigger a false alarm or even a real maritime emergency.
But how do you test emergency transmitters without triggering an alarm? Having the manufacturer modify them so that they send a test signal instead of a distress signal is out of the question; after all, series devices are to be tested. After a few discussions with the MRCC in Bremen, the plan was finalised: we would provide the sea rescuers with the serial numbers and MMSI of the transmitters in advance and stay within a defined corridor. We also notify the control centre of the start and end of the test. So far, so good.
The devices were ordered, the serial numbers were sent and a test day was arranged. A boat, dinghy and crew were organised and the photographer briefed. For the practical test, the transmitters are to be fitted to a lifejacket and triggered. The whole thing is then towed away from the anchored yacht by dinghy to check when the radio connection is lost. But after a short time, the distress control centre contacted us by phone. The officer on watch kindly asked how much longer we needed. I explained to him just as kindly that we had only just registered and would certainly be working with the transmitters until the afternoon.
The next few hours went according to plan, one AIS MOB after the other was activated and surveyed, then the phone rang again. It turned out that although the emergency transmitters are not an official part of the rescue chain, an alarm went off in the control centre every time they were activated, and not just in the German one. The Danish sea rescuers also had their hands full. Although they were aware of the test and had the list of affected MMSIs, they had to acknowledge each alarm manually and were getting fed up with the hours of continuous sounding. Their software was unable to distinguish between test mode and emergency mode. The Danes therefore called their colleagues in Bremen after every alarm, who then contacted us. But things were about to get even better.
A long day at sea
The relief of the rescue officer on watch was almost palpable on the phone when I cancelled our last transmitter in the late afternoon and declared the test complete. As we also wanted to check the visibility of the signalling lights, the sun had long since set by the time we got back to the berth after a long day at sea. As a result, breakfast was scheduled for half an hour later the next morning and the equipment was only given a makeshift clear-up before we fell tiredly into our bunks.
Thanks to the bright sunshine, breakfast was taken in the cockpit, apparently with a harbour cinema. A coastguard patrol boat pulled up to the harbour, stopped and lowered a heavily motorised dinghy. The officers steered unerringly towards our pit lane, passed our stern and then drove round all the other lanes. After the rib had done a lap of the harbour, one of the crew jumped ashore and ran to the harbour master's office. He came back shortly afterwards, the officers did another lap of the harbour, greeted us in a friendly manner and made their way back to the mother ship, which picked them up and steamed off.
What was that? Did they ask the harbour master for directions? The harbour master provided clarification minutes later. He stood at the bow and asked:
Aren't you guys using distress beacons? You'll have to look for the off switch."
The coastguard had picked up a sporadic AIS MOB alarm, but shortly before reaching the harbour the signal had finally disappeared from the screen so that they no longer had a position. Hence the inspection trip and the enquiry to the harbour master.
"Can't be ours, we've switched off all the transmitters and cancelled them with the control centre," I replied with conviction. But as soon as I had said the sentence, I started to feel a certain unease. After all, it had been really late yesterday and I had thrown the box of transmitters under the lounge bunk myself, somewhat unmotivated. Could a device have activated itself in the process?
But why had the alarm only been raised now and why had it only been raised with the coastguard? After yesterday, there was no question that the sea rescuers had my phone number. So I made my way into the saloon, dug out the box and inspected our MOB transmitters. Sure enough, the magnetic switch for automatic activation on the lifejacket was missing from one of the devices. But the transmitter had been deactivated manually. Relief spread. So the alarm really hadn't come from us.
Suddenly there was a flash in the corner of my eye. It was the signalling light of one of the other AIS MOBs. But this was also deactivated, was I wrong? Probably not, because now the on-board plotter, which had been switched on in the meantime, was also reporting the reception of an AIS MOB signal. I frantically fingered the transmitter, the switch was clearly set to off, but the device was still active. The battery could not be removed, so how could the transmitter be silenced?
On diving station
In my mind's eye, I could already see the crew of the patrol boat jumping into the dinghy. That gave me an idea: the thing has to go under water! Unfortunately, the devices float. First of all, I had to get onto the bathing platform and submerge the antenna, which should have taken care of the range. While I crouched at the stern, a colleague made a small anchor harness: with a winch handle as ballast and a long tether, we finally sank the transmitter behind the stern. The instructions promised a battery life of around 24 hours, so we towed the transmitter throughout the day to be on the safe side.
Why the AIS MOB was sporadically going on air despite manual deactivation could not be conclusively clarified. After we had sent it to the diving station, it was full of water, and even the manufacturer could no longer determine with certainty whether the leak had already been present. The fact that only the coastguard had received our alarm was due to the storage under the saloon berth, so far down in the boat it simply had hardly any range.
