There's an unending debate over at CPF (the flashlight board) on whether it's worthwhile having SOS (i.e. the flashlight has a setting where it flashes SOS) in a flashlight that already has a strobe function (steady pulsed flashing). The issue with flashlights is that more functions complicates the interface, so one side says get rid of the SOS function: if SAR is looking for you then the plain strobe will get their attention just as well. The other side says a non-SAR observer might interpret the strobe as some non-emergency signal but SOS always means SOS. I myself would say that SAR by definition means a person is known to be missing, in which case any signal will be investigated, so SOS is likely only of value when the person is not known to be missing but might be spotted by an accidental observer. I wonder how likely it is that a non-SAR observer will spot such a signal anyway.

Does the equpped.org or SAR community have anything to say about this?

I am not SAR. That said, I can guarantee you that I would most likely ignore a steady strobe, but if I were to see an SOS I would definately investigate it. If strobes are becoming that common I may treat them the same from now on.

Edit: Come to think of it, I saw an activated strobe on my way to work this morning. It was attached to a bicycle that somebody was riding along the road in the dark. It was very effective as a warning to other drivers, but the rider did not appear to be in any distress. Given such uses, I think I'd stick to SOS for a distress signal. Less chance of it being mistaken for something else.

Excluding marine use and .mil use, I wonder how many folks have been rescued by flashing a strobe or an SOS?

Is this debate over flashlights only?

I ask because if you are considering this for an actual rescue strobe (as in the xenon strobe type like the ACR Firefly series), then having them emit an SOS signal is impossible as fas as I know. The xenon bulbs that those strobe lights use are much like the flashbulb in cameras (or maybe even exactly like them). The don't have separate settings for dits and dahs. They are designed to only do short, albeit blindingly bright, dits.

If you are talking about a flashlight emitting a constant flashing versus an actual SOS, then my opinion is why the hell not. Most flashlights that have a flash/SOS function are LED lights anyway. The electronics to make an SOS and a constant flash are pretty much the same as the electronics that make just a constant flash, it's just a different IC chip. That different IC chip certainly isn't too big to include in the light, and the Photon micro-lights prove it. (They have both the constant flashing [3 speeds] and the SOS function built-in and look how small they are.)

As far as the "extra" SOS mode complicating the interface, I feel that if your flashlight does more than turn on and turn off, the interface is already too complicated for 50% of the population to figure out. What's another mode gonna do? Make it so 51% don't get it? And you know what those people who don't get it are gonna do? They're simply going to turn the flashlight on, then either stick their hand in front of it or sweep the light side-to-side in intervals required to make constant flashing or SOS.

Good question.

Did you read about that solo climber they rescued a few weeks (?) ago. He got stuck on a small ledge, activated his PLB, and waited for rescue. For some reason they started searching in the wrong place (never heard the real cause of that - I suspect they only got a Doppler location) and he watched them for hours off in the distance searching in the dark until searchers gave up and waited for daylight. He tried to wave his emergency blanket at them but they didn't see him. It wasn't until the next day that a helicopter finally saw him waving the blanket.

If he had some kind of signal light (Rescue laser light, strobe, or SOS - heck, even a decent flashlight) I'm pretty convinced that he would have been noticed/found much sooner.

Though it is a marine use, I was struck by the "I Shouldn't Be Alive" where two divers were swept out to sea and boat searchers and later helicopters couldn't see them at night (the divers didn't have a flashlight).

Unless the light was coming from an area where I KNEW someone shouldn't be (like on the side of an uninhabitted mountain) I would likely ignore a strobe, but I might be drawn to wondering why a light would be blinking in an SOS pattern. On the other hand, if out in the wilderness, any light might be of interest.

BTW, I just got one of those little Fenix P1D Cree lights. It has an SOS setting, but the way they made the light rotate through the modes (if any mode is on more than 2 secs a rotation only turns it off - I don't have to flip through all the modes - Med>High>Low>Strobe>SOS - each time) , it really won't get in my way. Princeton Tec headlamps do that same thing, though I don't think either my EOS or Aurora have SOS modes - just the strobes.

Yes, this is about LED flashlights. The interface complication is that you have to cycle through all the different modes and functions to get to the one you want, so there's advantage to having as few modes as possible. It's less a matter of confusion than avoiding imposing inconvenience on doing the most common operations (i.e. just turning the light on and off) in favor of functions that you'll likely never use.

I think that a blinking light in the middle of nowhere is going to cause comment. And be investigated.
Any one with any sense has told a responsable person that they are going to.......... via .................and expect to be there by.......... They will phone/radio the R.P. when they arrive. If they don't phone/radio by ........... please contact the emergency services.

L.E.D. headlamps are much more robust than strobe light's, which are somewhat vunerable to sharp impacts breaking the flash tube.
It might be worthwhile to have a write in to manufacture's asking for a S.O.S. or 3 flashes, pause, 3 flashes setting. Reviewers might want to pass specific comment. Which would make manufacturers take notice.

Dont most SAR flights cease at night?

Being on SAR, if you are searching a specific area, particulary at night, ANY light in the woods would be investigated. If it were too far away, it would be radioed in to another team, or a helo if one were available. In MA, the state PD was given a grant for a helicopter a few years ago fitted with FLIR, that has helped immensely with searches for Alzheimers patients.
touching on all that, in MA, ONLY certified searchewrs are allowed on search teams, per state police regs. All of us folks would recoginze ANY lights for what they were. However, we dont normally run into folks who are well prepared. Case in point: A hunter got caught out, after dark, in November. The guy wasnt prepared, at all, for cold weather (why, who knows). His wife didnt report him missing until 8:30 or so at night. He walked out, as we were assembling to start the search. He was less than a mile from his truck, on a busy road, in a state forest. No flashlight, no whistle....only a canteen & his shotgun. He was local, and thought he knew the area. Would we have gone looking for him, all he would have had were his shotgun to shoot (if he would do that), or his voice. Without a flashlight or whistle, he could have been in for a long night. Its the simple things folks leave behind, thinking they are OK. I mean, come on, how much does a flashlight weigh? Nothing. People just plain old arent concerned with their own safety.

I am not SAR. Personally I like my flash lites to be simple. It's not that I can't figure out how to use them, but I find having to cycle through multiple modes to be annoying.

Additionally, I don't think SOS should be built into a regular flash lite. As mentioned earlier a normal person would ignore a strobe, but may respond to SOS. If a SOS feature is an available setting on a flash lite, I feel it would become overused by the general public and start to lose it's meaning.