Medical Emergency Call
Diver Dave must have just come up from the DEEP ;>, although he did mention SSB & ham, if you carry 1 on board and a landline, which I'm not too sure how you would do that.
As was also brought up, a cell tower may not be close at hand. VHF does also have it's limitations, depending on how high your antenna is.
Explore Anywhere. Communicate Globally.
Using the worldwide coverage of the Iridium satellite network, these go-anywhere portable devices let you exchange text messages with any cell phone number or email address — while using GPS to track and share your journey’s progress. You can also post to social media or even communicate inReach-to-inReach in the field.
In case of an at-risk situation, you can also use inReach to trigger an SOS to the 24/7 monitoring center, text back and forth about the nature of your emergency, and receive confirmation when help is on the way
As to 3rd party responders, let me add this;
Who Will Answer Your SOS? GEOS Will.
GEOS is the world leader in emergency response solutions and monitoring. They’ve supported rescues in more than 140 countries, saving many lives in the process. And they’re standing by 24/7/365 to respond to your SOS, track your device and notify the proper contacts and emergency responders in your area. Then, while help is on the way, GEOS will continue to text back and forth with you, providing updates and critical information until your situation is resolved. Watch this
informative video to learn more.
An EPIRB or PLB will tell people where you are but not what is going on. Would you like to have someone show up with a bandage for a heart attack?
We all know that there is NEWS, that has brought up issues with 'services' like GEOS, SPOT uses something similar, but we also know we can always trust the news media to only report the facts, right?
I think at this point, I've added all I can add.
Just realize that there are alternatives out there and keep an eye out, it changes all the time.
Stay safe out there.