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Telstar 28
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Discussion Starter #1 (Edited)
This past Christmas, I received a SPOT Messenger. I didn't activate it until just recently, when I was helping deliver a sailboat from Annapolis to Marion, Mass. The reason I decided to activate the SPOT service was so that several of the families and friends of two of my fellow delivery crew would be able to keep an eye on them, since this would be their first major passage.

The SPOT Messenger is a small GPS-based satellite transponder that uses the GlobalStar satellite network to transmit location and time data as well as one of four types of messages. The four message types are:
  1. I'm OK
  2. Help
  3. 911—send help
  4. Tracking update
The first three message types are included in the basic $99 annual service.

The "I'm OK" message is basically just that... to let people know where you are and that you're okay.

The "Help" message can be tailored via the SPOT Messenger website to be a "call me" or "send money" or some other type of message, that requires some action on the part of the persons monitoring you.

The "911" message will result in the SPOT Message service center calling the authorities to respond... and should only be used in a true emergency.

Please note: While some people think that the "911" feature will replace an EPIRB, I disagree. First, the SPOT Messenger relies on the Globalstar satellite network, which has some serious issues. Second, an EPIRB or PLB acts as a SAR Transponder and broadcasts a 121.5 MHz signal to help SAR personnel locate you. Third, the run time on the EPIRB or PLB and durability of the units is probably much greater.

The fourth type of message is a tracking message, and it requires the real-time tracking service, which costs an additional $49 per year. To send these messages, you put the SPOT into tracking mode. These can then be seen on a SPOT tracking page.

There are a few issues IMHO with the SPOT and its tracking mode. First, tracking mode is only active for 24 hours, and then it needs to be re-activated. Second, tracking mode sends a message out every ten minutes, which is a bit too short a time interval for most sailboat tracks.

Personally, I think that tracking mode should stay active until it is deactivated. I also think that there should be some other intervals for tracking messages, say 10 minutes, 1 hour, and 6 hours or something similar. This would make tracking boats much simpler, since the SPOT would operate for about a month if it was allowed to send messages every hour instead of every 10 minutes.
 

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I really like SPOT because I can let friends and family know I'm doing fine and provides my position. It gives my wife some comfort while I'm at sea - if she's happy, I'm happy. In fact she's more agreeable to my sailing adventures, which is a good thing.

I don't use the tracking mode, but rather I just send a OK signal every so often.

I wouldn't go to sea without and EPIRB but then again, an EPRIB does do what I described above.
 

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Does the SPOT have world wide coverage? If they are using Globalstar's satellite network, that might not be the case. Anyone know?
 

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Telstar 28
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Discussion Starter #5
The main reason I set up the SPOT in tracking mode was because our route wasn't set in stone when we departed. We had a choice of going up to NYC and through Long Island Sound, or off shore from Cape May to Block Island. We decided on the off-shore route, and avoided the really heavy weather that clobbered LIS.
 

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Sea Slacker
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Please note: While some people think that the "911" feature will replace an EPIRB, I disagree. First, the SPOT Messenger relies on the Globalstar satellite network, which has some serious issues. Second, an EPIRB or PLB acts as a SAR Transponder and broadcasts a 121.5 MHz signal to help SAR personnel locate you. Third, the run time on the EPIRB or PLB and durability of the units is probably much greater.
I think this is not entirely true.

1) 121.5Mhz EPIRBs have been completely phased out afaik, and current EPIRBS produce no local signal of any kind. The SAR relies on the 406Mhz signal and, preferably, the GPS location sent with it.

2) EPIRB signal registration with Coast Guard is not instantaneous. In fact, according to people that run Boston center that listens to EPIRB signals, it may take up to 12(!!) hours for them to get the signal. Don't ask me why, but thats what they say. Perhaps there is some handoff between the satellite network and their equipment.

3) EPIRB coverage has its own gaps. On the other hand, Globalstar simplex network that is used by SPOT is in good shape and has no known issues.

4) There is no way to know whether your EPIRB works until you actually use it, when it may be too late. As an engineer, I can't rely on any "self test". The only test of the device is actual activation and receipt of signal, end to end. SPOT is tested virtually all the time.

5) SPOT in tracking mode provides past history of your movement, as opposed to EPIRB which is essentially a single point. This may be very important in SAR because if they know where you've been they may have easier time finding where you are going.

So, personally, I think SPOT has a number of advantages over EPIRB. That said, I would prefer to have both for any offshore sailing - you never know what gives :) Locally SPOT is my choice.
 

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SD, thanks so much for posting this message.

Few questions ...

1) When you send an "I'm Okay" message, do you get any feedback that the message has actually hit the satellite, or even better that it was received by the center that processes the messages ? Or do you just push the button and hope for the best ?

2) What kind of batteries does it take, just regular "AA" type batteries or does it have special batteries in it and special charging requirements ?

3) Do you know if there are any third-party devices that use the network or is it exclusively the one SPOT device ? Not that there is anything wrong with the one SPOT device, I am just curious if there are options. :)

Thanks again.
 

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Sea Slacker
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I know I am not SD, but I'll answer anyway.

1) the uplink used by SPOT is "simplex" - i.e. one way. SPOT has no idea whether its message is actually received by anyone.

2) SPOT people insist on lithium batteries. They are AA in size. The manual says using regular (non-lithium) AA will cause all sorts of bad things to happen. I guess at a very least they will run out a lot sooner than lithium.

3) There are many other devices that use Globalstar simplex uplink but none of them are "end user" devices and they don't come with any usable "backend" (i.e. they are "modems" and if you have your own telemetry application you can probably build one using it). SPOT is Globalstar's own product and I would guess they are not likely to let anyone else sell similar devices - they need the money :)
 

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A month or two ago my buddie hopped on my boat for a little 2 hour sail in the Long Island Sound from one marina to the next for me to have my boat hauled. He brought his SPOT messenger to test it out and also even though the weather was nice, it was so early in the season that no other boats were out.

Anyway he said he hit what ever button sends messages out to whoever he had set up in his account to receive them which included him and I, yet no messages came up on our phones. After we got back he found out that due to a billing error that wasn't fault his service got turned off. So no problem with the device but I guess its best to make sure your service is still working prior to a long trip.

We did wonder though what would happen if we hit the 911 button if in an emergency they would alert SAR personnel or say screw those cheapos for not re-newing the service!:eek:
 

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It can't be one way communication only because SPOT does give you a signal that the message has been received. I believe both lights stay on for a few seconds. I wish they stayed on longer because it's easy to miss the signal.

Again, I think it's a very useful tool.
 

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Telstar 28
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Discussion Starter #12
I think this is not entirely true.

1) 121.5Mhz EPIRBs have been completely phased out afaik, and current EPIRBS produce no local signal of any kind. The SAR relies on the 406Mhz signal and, preferably, the GPS location sent with it.
Brak—

The 406 MHz EPIRBs still broadcast a 121.5 SART signal. From the ACR website on a GlobalFix 406 MHz EPIRB

Transmits on 406 MHz (COSPAS-SARSAT) with your registered, unique, digitally-coded distress signal, and 121.5 MHz (SAR homing frequency)
2) EPIRB signal registration with Coast Guard is not instantaneous. In fact, according to people that run Boston center that listens to EPIRB signals, it may take up to 12(!!) hours for them to get the signal. Don't ask me why, but thats what they say. Perhaps there is some handoff between the satellite network and their equipment.
That isn't much different from what happens at the SPOT messenger center when you push the 911 button.

3) EPIRB coverage has its own gaps. On the other hand, Globalstar simplex network that is used by SPOT is in good shape and has no known issues.
The COSPAS/SARSAT network is a lot more reliable and has broader coverage than the Globalstar network, which has well-known satellite reliability problems.

4) There is no way to know whether your EPIRB works until you actually use it, when it may be too late. As an engineer, I can't rely on any "self test". The only test of the device is actual activation and receipt of signal, end to end. SPOT is tested virtually all the time.
True, but modern manufacturing systems and field use of the EPIRBs means that they're pretty reliable.

5) SPOT in tracking mode provides past history of your movement, as opposed to EPIRB which is essentially a single point. This may be very important in SAR because if they know where you've been they may have easier time finding where you are going.

So, personally, I think SPOT has a number of advantages over EPIRB. That said, I would prefer to have both for any offshore sailing - you never know what gives :) Locally SPOT is my choice.
Very true, but the SPOT Messenger doesn't have the proven field track record that the 406 MHz EPIRBs have yet.
 

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Telstar 28
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Discussion Starter #13
No, it does not acknowledge the message receipt AFAIK.
It can't be one way communication only because SPOT does give you a signal that the message has been received. I believe both lights stay on for a few seconds. I wish they stayed on longer because it's easy to miss the signal.

Again, I think it's a very useful tool.
 

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old guy :)
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We have a SPOT - we love it! We are taking our new to us Irwin Citation 34 home to Canada from Annapolis MD. We push it around noon and when we reach our destination. Or other times if we are near something cool - like the Statue of Liberty or half way through the C&D canal.

If you want to see what it looks like - look at our sailing blog at:

trip blog at: Mystery - the Trip Home

Rik and Linda
Mystery
Irwin Citation 34
 

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Sea Slacker
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It can't be one way communication only because SPOT does give you a signal that the message has been received. I believe both lights stay on for a few seconds. I wish they stayed on longer because it's easy to miss the signal.

Again, I think it's a very useful tool.
That signal is just a notification that SPOT is "no longer sending". It does not mean SPOT knows that message was received. In fact, SPOT will tell you that "message was sent" even if it actually was not. Simplex is "one way".
 

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No, it does not acknowledge the message receipt AFAIK.
I use my spot for backpacking all the time. I think the confusion may be that the SPOT does not let you know if a tracking messages has been successfully sent. However, it does let you know if an OK, HELP, etc... message has been sent. The corresponding light will continue to flash until the message has been sent. If I recall correctly 2 solid lights will indicate a transmission, and 2 alternating lights indicate a failure. However, even after a failure a the light will continue to flash until the message has been sent. No flashing means the message was successfully sent (unless you have turned on tracking mode in which case the light will always be flashing).
 

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I use my spot for backpacking all the time. I think the confusion may be that the SPOT does not let you know if a tracking messages has been successfully sent. However, it does let you know if an OK, HELP, etc... message has been sent. The corresponding light will continue to flash until the message has been sent. If I recall correctly 2 solid lights will indicate a transmission, and 2 alternating lights indicate a failure. However, even after a failure a the light will continue to flash until the message has been sent. No flashing means the message was successfully sent (unless you have turned on tracking mode in which case the light will always be flashing).

SPOT does not know if a message was sent. There is *no* downlink from the satellite back to SPOT. It is a one-way communication, no matter what lights show.

Globalstar - Wikipedia, the free encyclopedia - read about "simplex".
Simplex communication - Wikipedia, the free encyclopedia
 

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S/V Lilo, Islander 32
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I think the confusion may be int he terminology, SPOT can tell you it sent the message, but doe snot know if it was received by the satellites or any other systems on the other end. Of course I do not own one, so I am not sure, but I think that's what the diffrent people might be saying?

I am a gadget geek and think the spot is very cool and useful, however I fear that on a long trip, if we set up to send messages every so often so people know we are OK, I know I will drop it in the bilge, let all the batteries die, or some how break the system and freak the family out when we do not check in for a few days.

I am still pondering if it is better to tell them "We will be fine, don't worry" and not check in regularly, or check in, but risk a major panic attack due to an accident?

I am thinking to get one, but only send an OK message if we are long over due but still OK. Kinda halfway in between. Being over due is likely, breaking the thing is likely, but having both go wrong and start a panic is a bit less likely.

Any other thoughts on the psychological side of spots on long distance cruising?

Thanks
Bryan
 

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I am a gadget geek and think the spot is very cool and useful, however I fear that on a long trip, if we set up to send messages every so often so people know we are OK, I know I will drop it in the bilge, let all the batteries die, or some how break the system and freak the family out when we do not check in for a few days.
I had spot operate for 3 days in a row. I also used the same set of batteries to operate it intermittently (4-5 hours a day) for an entire sailing season, many weekends. According to manual with appropriate batteries it will work in tracking mode for 14 days, and I think that's about right.

On my boat I have a place under the hardtop where it sits clipped on a piece of webbing, so it's easily accessible but can't go AWOL and is out of the way.

I realize it's limitations but I think it's features are certainly worth more and overall no other device gives that much good functionality for such (relatively) small price.
 

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Dawg,

Nice write up, but there is one thing wrong with #1 in your case.:rolleyes:

1. I'm OK
2. Help
3. 911—send help
4. Tracking update
I think it's a false statement. :D
 
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