If it's a matter of life and death, such as offshore fishing, you probably want a real commercial service.

Like Garmin (Iridium based texts back and forth) or Zoleo. These are physical units that may offer texts or just a simple "sos" button.

Or a recent iPhone will communicate with Starlink, or T-Mobile offers a similar system for Android phones and is also based on Starlink. These can exchange texts which is much more reassuring than a simple sos button.

Of course offerings outside the US may be limited or entirely absent.