Iridium 9575A is the only real choice and is pricey. But it might save your life! Civilians can own one too.

The 9575A Satellite Phone is a military-grade 810F global satellite phone for government customers and offers an ingress protection rating of IP65, shock/water resistance and complete voice, data, and tracking capabilities.

https://www.ipinternational.net/glob...-push-to-talk/