Emergency Position Indicating Radio Beacons (EPIRBs) are designed for marine use. Hikers and travelers should use a Personal Location Beacon (PLB).  SPOT is a brand name for a satellite messenger and tracking device.
See https://www.rei.com/learn/expert-advice/personal-locator-beacons.html for an explanation of how the devices work and what they cost.
PLBs and satellite messengers can be rented.