Are you sure you need voice?
I've found my Delorme Inreach (now owned by Garmin) connected by bluetooth to my iphone
to be a great solution to offshore
communication. A fraction of the cost of what you're looking at. Always works. Works everywhere. No external antenna
. It sits on my chart table and transmits through the fiberglass
overhead just fine. SMS or email
send/receive. As anyone under age 30 will tell you, if you can't say it 160 characters, it's not worth saying
They also now have a much improved weather service
- on demand 5 day forecast
for any lat/lon for $1. Not as good as a wide area GRIB but good enough for me.