I’d look for a more reliable solution.
We are looking at them as a more reliable solution than mobile phones, for folk in remote but not particularly dangerous locations. An advantage over epirb would seem to be that they can be used to check in – that they are OK, give a heads up that they have a problem – but not life threatening, or HELP.
Where are they unreliable?
Maybe we need to get one to trial it first.
Point taken – £100 is not a bad deal!