Distress Signals

Posted on Wednesday 13 July 2011

One of the most important pieces of safety gear are distress signals. There are many kinds of distress signals, but they fall into three categories as a general rule.

Visual Distress Signals:

These include flares, smoke, flags, mirrors, waving your arms, strobe lights, etc. They are designed to attract attention to you or your boat visually. I’ll be going over each of these different types of visual signals.

Flares are probably the most common visual distress signal. They are usually pyrotechnic based, and can pose some risks to the user. You can get either USCG-approved or SOLAS-approved flares. I personally recommend the latter, and think the USCG-certified flares are a waste of money and possibly a danger.

SOLAS-approved flares are far brighter and longer-burning than their USCG counterparts as a general rule. A USCG-meteor flare has a burn time of about SIX seconds. A SOLAS-approved parachute flare has a burn time of over a minute in most cases. It also is brighter and flies higher and hangs in the sky for the duration, making locating your vessel much simpler.

There are also hand-held flares. The USCG-approved ones can drop hot slag, which can pose a danger to the user and the boat. The SOLAS-approved ones do not drop slag as far as I know. They are also usually brighter, and visible from a farther distance than their USCG-approved counterparts.

Smoke cans, flags, and mirrors are basically day-time only signals, and of limited utility as such. However, in calm weather and conditions, the smoke cans can leave a highly visible mark for SAR personnel to find. Mirrors are great for the ditch bag, as they don’t require batteries and don’t care about getting wet. However, the range on them is somewhat limited and only useful in the daytime.

Waving your arms and strobe lights, unless they are mounted atop the mast, are pretty useless as signals to other boats. They can be useful at fairly short ranges, and I recommend that every PFD be equipped with a strobe. At close distances, the strobes are less useful, and having a small flashlight on each PFD will be useful.

One recent development is the laser flare. It is a flashlight-sized unit that uses a semi-conductor laser to generate the distress signal. These are quite nice and, if equipped with long-life lithium-type batteries, can be a good addition to a boat’s distress signals. However, they are generally not USCG approved, and do not count towards the three day/night signal requirement on larger boats. Unlike the standard laser pointer, the laser flare produces a wide stripe of laser light, and makes hitting remote targets, like SAR planes or other boats much simpler.

Audible Distress Signals:

These are usually horns, whistles and bells. The bells are generally ship-board use only, as are most of the horns. For small craft horns, I like the Eco-horn, which uses compressed air and is filled/pressurized using a standard bicycle air pump. This makes it far more environmentally friendly than most “air” horns. It is also fairly loud, though a bit higher-pitched than one might want.

Whistles are excellent for signalling at short ranges, and I highly recommend every PFD have some sort of whistle attached. I like the Fox whistle and the Storm Whistle, though the latter is a bit bulky.

Electronic Distress Signals:

These are usually broken down into EPIRBs and PLBs, though recently, a new class of less robust “Messenger” type devices has come along. There are significant differences between EPIRBs and PLBs.

EPIRBs are registered to a specific vessel. The EPIRB registration has a clear description of the vessel, the maximum number of occupants, the owner’s contact information and such. The EPIRB is a larger, bulkier device, and has a greater run time than the smaller PLBs generally do–48 hours versus 24 hours typically. An EPIRB is also designed to float and work while floating. Most have a water-immersion automatic switch. They also generally have a strobe as well as a SART 121.5 MHz beacon. Many have an integrated GPS to allow them to broadcast updated, near-realtime position information.

PLBs are smaller and registered to a specific person typically. Many will not float, and few will work if immersed or floating in the water. They do not have a strobe and few have an automatic switch of any kind. Some of the newer ones do have the integrated GPS featured in the larger EPIRBs.

EPIRBs and PLBs both have an integrated battery that is not designed to be user replaceable. The battery is a long-life lithium-based one that is generally good for about five years.

The new “Messenger” type devices are the ones that were inspired by the Spot Messenger, which I’ve written about previously on this blog. Most report back through satellite phone networks, rather than the dedicated COSPAS/SARSAT system the PLBs and EPIRBs use. Some can report back with user-editable messages, others are forced to use “canned” messages. They are often used for tracking boats, but have some emergency features. However, I do not believe that “Messenger” type units are sufficient to replace either EPIRBs or PLBs. The fact that they are not as robustly built, have much shorter battery life, and use the commercial satellite phone network for data transmission are serious limitations on their reliability.

VHF, SSB and Satellite phones can also be considered “electronic” distress signals, but serve far more purposes than just distress signalling and are outside the scope of this article.

A well-found cruising sailboat will have a mix of the above aboard, with the individual PFDs being equipped with strobes, flashlights and whistles. The EPIRBs and PLBs are not really a necessity unless making longer, open-ocean passages. For daysailing or coastal cruising, the visual and audible distress signals are generally all that would be required under most circumstances.

One thing I highly recommend is getting some actual experience using the flares. You do not want to be learning how they work in an emergency. Proper training will make their use far more likely to succeed.

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