What it is
Iridium Certus is a connectivity service running over the Iridium NEXT constellation of 66 cross-linked low-orbit satellites, using L-band with compact terminals on board.
Why it matters
Because the constellation covers the entire planet, including the poles where geostationary satellites cannot reach, Certus is a uniquely resilient backup for vessels on any route.
Safety role
Iridium is an approved GMDSS provider, extending mandated distress and safety coverage to the whole globe, including high-latitude waters.