Really different tools for different purposes.
The EPIRB is for a Mayday situation. You are declaring a current
life threatening emergency
. Send the helicopter. It's not appropriate for PAN calls. I've never activated my EPIRB. Most people haven't. But at $400 how could you not carry one offshore
The Inreach is useful for a wide range of offshore short communications
. It works anywhere in the world because it uses the Iridium
network. It provides reliable two way communication in 160 character messages to anyone with an email
address (and they have their own staffed emergency
center). It's waterproof and has a four day battery
life. It's a great backup for SSB/Ham radio
. Much less expensive than a sat-phone. I primarily use mine to keep in touch with family
and friends on multi-day offshore trips. I did use it once to get advice from the mechanic
at my home boatyard about an engine
problem. It won't receive GRIB files but someone ashore can send you weather
reports and weather
routing. Ocens also offers a limited weather service
The Inreach will not browse the web, do longer emails, pictures and blogs. You will need wifi
or the phone/sim card and be close to land. "Poaching wifi" has also pretty much gone away. You will be paying for wifi
access or paying for data on a sim card. Which one will work better will depend on the island and the harbor. Most people do both.
I couldn't tell from your original post whether your plan was to stay close to land or do multi day offshore passages. If the latter, an EPIRB alone isn't enough. I would carry either 1) EPIRB and SSB/Ham, 2) EPIRB and Sat-phone or 3) EPIRB and Inreach. The Inreach option is the cheapest of the three.