Paul,
I 'd agree that battery life per se is not an issue. It 's more that having to remember to do something manually might be - switch on, switch off, change the batteries... The more I can eliminate my human errors, the better.

I 'm thinking of the folks who use an SSB to send a daily message "I 'm OK", and then one day that message doesn 't get sent, for some trivial reason (bad connection, corroded wire) and then the folks shoreside phone the Coastguard, and set a rescue mission going. It happens.

I 'd say that just to send my noon position is quite often enough for the tracker to be operational, but I might want to receive messages more frequently.

Yes, Mike Richey told me that on his annual trip across the Atlantic in Jester,, he would switch his GPS on for 5 minutes at noon, just to check the fix he was getting from whatever esoteric, archaic navigation tools and methods he was experimenting with - and made the batteries last for the whole passage.

David,

I think battery life is an issue with all of them, but only if you keep them switched on all the time. To be honest, I can 't see a real need to be tracked every ten minutes, or even every four hours.
I work on the basis that I let the folks back home know everything is OK ever 36 hours,or so.
I just switch it on for a while, send a tracking signal, and if the message light is flashing I 'll download that. I can 't give you a figure, but I guess that batteries would last for weeks that way.

On a similar subject, a friend of mine went from Falmouth to C Horn and back on quite a spartan boat. All they carried was a pocket GPS which they switched on at noon to get a fix, and then switched off again.
Their proud boast is that they got from the Horn to Falmouth on one set of AA batteries!

I found this link to the Cerberus device in that blog: http://cerberus.briartek.com/cerberlink/specs
That 's one I hadn 't heard of, it looks quite interesting, and it has a rechargeable battery...

David,
Yes that is right

Paul,
I looked at SPOT first. The pricing is good, but there 's a huge area of the Pacific that 's not covered. Wouldn 't be any good for going around Cape Horn, either!

I don 't think I 'd want to consider anything that needs its batteries to be replaced, though the electronics blog says there 's a power supply coming for the Inreach sometime.

Simon,
Many thanks for the comparison. But when I looked at the DeLorme site, the specs say that there is a GPS chipset built in. I 'd be surprised if there wasn 't, a device such as this wouldn 't be much use as an SOS panic button if some other bluetooth GPS had to be switched on as well.



David.

Since posting the above, I found this on an electronics blog. It was posted back in May and there have been a couple of software updates since.
The comments at the bottom make interesting reading - giving you the pluses and minuses

http://www.panbo.com/archives/2012/05/delorme_inreach_15_groovy_with_an_ipad.html

Simon,

Good work! You might also have a look at SPOT who have brought out something similar, although the satellite system they use has limitations at high latitudes.

As you say, this is a developing area and we 'll see some interesting stuff over the next few years. Anything is better (and cheaper) than a satellite phone for text messaging - for some reason I find them to be very user-unfriendly.

Paul Heiney
Wild Song

Thanks Paul it looks like there is lots of new kit becoming available that use the Iridium network. The Delorme certainly looks better value for money than Yellowbrick. I did a quick comparison just for my own interest but thought it worth sharing.

Delorme:
[ol]
[li]Uses Iridium[/li]
[li]Bluetoothe interface with iPhone or iPad[/li]
[li]AA batteries able to post position report every 10 minutes for 120 hours[/li]
[li]2 way messaging[/li]
[li]Sos button[/li]
[li]24/7 manned response to sos[/li]
[li]Compatible with Email, SMS, Facebook and Twitter[/li]
[li]$260 plus airtime plan[/li]
[/ol]


Yellowbrick:
[ol]
[li]Uses Iridium[/li]
[li]Bluetoothe interface with iPhone or iPad[/li]
[li]Rechargeable Ithium battery via USB position report every 15 minutes for 3 weeks or every day for a year[/li]
[li]2 way messaging[/li]
[li]Sos button[/li]
[li]No manned SOS call centre but the SMS could go to Falmouth ets[/li]
[li]Compatible with Email, SMS, Facebook and Twitter[/li]
[li]Around £400 (depending on functionality) plus airtime plan[/li]
[/ol]

David,

I 'm a UK citizen too. No problem to open an account.

David,


I 'm a UK citizen too. No problem to open an account.