Tracker questions
Why Does a Ship Disappear From a Tracker?
A missing ship marker does not automatically mean the vessel stopped transmitting or has a problem. Public ship trackers depend on reception, data access, processing, and display policies.
By TransitSatellite · Reviewed October 20, 2026
Coastal AIS has radio-range limits
Standard AIS uses VHF radio. Shore-based tracking therefore depends on whether the vessel is within usable radio range of a receiver network.
When a vessel travels farther offshore, a public service may need satellite AIS or another data source to continue showing frequent positions.
Update timing can vary
AIS reporting intervals depend on factors including vessel movement and equipment. A public provider can also process, delay, combine, or filter reports before displaying them.
Not every vessel has the same requirements
AIS carriage requirements vary by vessel type, size, operation, and jurisdiction. Smaller recreational vessels may not be required to carry the same equipment as large commercial ships.
Common questions
Does a missing marker mean the vessel turned off GPS?
No. The tracker may simply lack a recent AIS report or access to a suitable data source.
Why do offshore ships update less often on some free trackers?
A provider may rely heavily on coastal receivers or offer satellite AIS only through a different service tier.
Sources
Port Canaveral guide
Connect ship tracking to official cruise and port schedules.
Open guideExternal live ship map
Open a third-party live vessel tracking service.
Open map