On Sunday, March 30, 2014 8:37:22 AM UTC-7, kirk.stant wrote:
On Saturday, March 29, 2014 10:14:10 PM UTC-5, son_of_flubber wrote:

(snip)

So basically, the crew DIDN'T have a required EPIRB, and relied on SPOT (which is a nice inexpensive TRACKING device with some backup 911 notification capability) to save their butts, then ran aground on autopilot due to bad navigation - and SPOT (while it gave the location of the crash and a message that something was wrong - a partial 911 message) didn't work as well as a dedicted EPIRB.

There was no requirement for an EPIRB. EPIRB carry requirements are really for commercial vessels. So like typical complex accident situation here with more than enough blame to go around. Owner/Skipper, crew, SPOT/GEOS, US Sailing, race organizers, etc. etc. A race like this not requiring an EPIRB (starting at prices $500) is really surprising, but also think what could be done if they had SPOT and/or InReach tracking (in addition to EPIRB carriage) on the whole race fleet (I wonder how much "leeching" would be a concern there).

As I see it, SPOT pretty much worked as advertised. It showed position fixes up to the crash site. BUT IT ISN'T AN ELT, PLB, OR EPIRB! Neither is Inreach. I use my spot in my glider as a simple, reliable (and it has always been for me, YMMV) tracker. I also have an ELT. I don't care if others see my altitude or about a faster tracking interval, so Inreach's capabilities aren't worth the extra cost to me.


But the overall SPOT service simply did not work as advertised. You might sensibly understand things and realize the real value of SPOT (and InReach) is as a tracking service. Just fantastic. But SPOT/Globalstar makes more marketing claims than that. They don't advertise just a tracking service, or a GEOS provided "SOS" service that flounders around when the SPOT can't get a GPS position.

My problem with the original post is that it gives the impression that SPOT is an unreliable orange doorstop. In this particular example, it worked as designed until the boat was sinking - and then it only got a partial 911 message out - but was it still capable of sending position long enough after the crash to see satellites and get a position? THE BOAT RAN AGROUND AND SANK!

Is there data online about other "911" situations where SPOT/Geos has failed?

Yes, you can look for them as good as I can. And some are not clear fails, just too disorganized/slow for my liking. I remember reading some where folks were injured (broken arm in motorcycle accident IIRC) and thinking the delay to get resources to them was too long.

The technical aspect of this particular SPOT 911 activation that interests me is how long it takes to send a 911 message? That would be a useful bit of data.

RT*M. Seriously, its in the manual. When you you press "SOS" (aka "911") and the message is sent within one minute with or without a GPS fix. And is repeated at 5 minute intervals until the battery runs out. If it gets a GPS fix during that time (techncially within the first 4 minutes of each cycle) that then that is included in the next 5 minute transmission. Gen 2 and 3 manual numbers, I think gen 1 was the same.

What is the reliability of the SPOT system on the whole?

Nobody can really know that, Globalstar can model it, but broad "reliability" numbers may not be that useful.

Users can guess for their own use by say looking at dropped track messages or go try sending OK messages in different situations. (but remember an OK message failure to go though is the failure of multiple (3?) send attempts to get out, or there was never a GPS fix). And you cannot tell by looking at OK or track messages if the problem was lack of GPS or lack of a Globalstar satellite in range, since (unlike an SOS message) in both those cases no GPS fix means no attempt to send a message. You can only tell if lack of GPS was the issue by watching the "GPS" LED on the unit. I'd much prefer SPOT devices light up the GPS LED if there is no GPS fix, like they do, but then also try to send an OK or private message or track report with an "unknown GPS fix" -- that is potentially getting out useful data, and a useful troubleshooting tool for say dropped track messages.

Success/failure in specific scenarios will vary enormously, and it is really only the failure rates for a situation that you are more likely to encounter that matters, e.g. push the SOS button and then jump into the ocean holding it in your hand (for this yacht scenario?) or be under a forest canopy while hiking, etc.

The Globalstar L-band simplex data service that SPOT uses is inherently unreliable, by definition, its simplex only. All a SPOT tracker can do is fire and hope there is a Globalstar satellite in range, which is why they repeat certain messages. I have absolutely no argument that SPOT is capable of being a very useful tracking device if installed/positioned with a little thought (but InReach is all around better).

That is why I called BS on the tone of the original post.

The tone did get me too. I wish that original quoted article had used less goofy/stupid language, it is easy to dismiss it until you read the other media coverage (LA Times, etc.) or certainly the full US Sailing report.

Darryl