Iridium vs. Inmarsat vs. Thuraya: Which Network Actually Covers Where You Are Going
The map on the box says global. The map that matters is the one over your head at three in the morning.
You are anchored in a fjord north of the Arctic Circle. The wind has swung around and the anchor is dragging toward rock. You pull the sat phone out of the ditch bag, power it on, and stare at the screen. No bars. The phone is fine. It just can't see the satellite it was built for, because that satellite is parked 22,000 miles over the equator and the mountain behind you is in the way.