Despite our very good coverage worldwide, there are still some areas, where FleetMon doesn't have antennas yet.
A vessel sends its data to an nearby antenna or to a satellite. We have antennas all over the world with the help from our AIS Partners. If there is no antenna around, like on the open sea, the vessel must transmit the data via satellite. Satellite data is expensive, that's why we offer the Unlimited Sat accounts. With the Open and the Unlimited account you are limited to terrestrial data (antennas). With the mentioned Satellite account you can see every vessel in the world, even on the open sea and in ports where we have no antennas yet.