Beacons often incompatible with satellites. Designed for detection by aircraft. High number of false alarms is typical. 10-20 nautical miles accuracy. Search and rescue forces can home on the primary signal.
Beacon is coded with owners name, address, phone, vessel type etc.
No coded information with signal. Good ambiguity resolution, i.e. can promptly launch rescue unit to a known position with an alert from a single satellite pass. Hard to know which of two separate positions calculated with first satellite pass is the beacon location. Usually must wait for a second satellite pass to resolve. How, Inc .