How It Works

Passage Monitoring is a global free-of-charge service that monitors the progress of recreational vessels conducting ocean passages.

I use a range of tools, including satellite AIS, trackers, and email / HF radio reporting, to keep a constant watch on yachts that have filed a float plan prior to departure.

Whilst available to all yachts, Passage Monitoring is especially suited to short handed and solo sailors, in particular circumnavigators.

Check List


Your vessel must be fitted with an approved satellite tracker (list below) set to transmit position HOURLY whilst on passage.

  • Bivy Stick
  • Garmin InReach / Messenger
  • PredictWind GPS Tracking with Iridium Go!
  • PredictWind GPS Tracking with Iridium Go! Exec and Datahub
  • PredictWind GPS Tracking with Starlink and Datahub (automatic failover to Iridium Go! Exec backup required)
  • YB3 / YB3i
  • Zoleo

Additionally, you must provide a web site URL for your tracker that shows the track of your vessel over time, and the most recent position including time in UTC.

Trackers that use Starlink to send position updates without automatic failover to another satellite service are not supported.

Devices with inbuilt GPS are not supported on a steel or alloy vessel. YB3i or Iridium Go! Exec with Datahub recommended.

I recommend PredictWind GPS Tracking with a YB3i tracker for vessels wishing to use my Passage Monitoring service.


  • Complete a float plan using my prescribed form at least 24 hours and no more than 72 hours prior to departure.
  • Vessel has transmitting AIS, class B+ highly recommended.
  • Vessel must be able to send and receive email at sea (without a limit to the number of characters sent).
  • Captain must commit to sending a daily welfare report containing all prescribed data whilst on passage.
  • 24 hours prior to departure, captain files a float plan containing detailed information about vessel, crew and intended voyage.
  • Passage Guardian checks AIS and satellite tracker and configures notifications for vessel stopped, and sailing in high wind.
  • Passage Guardian confirms via email, receipt of float plan and provides an HF radio watch schedule (if available).
  • Please note that if you do not meet ALL of the prerequisties above, your request for passage monitoring may be rejected.
  • Vessel sends a Daily Welfare Report. If not received, Passage Guardian commences the Missed Check-In procedure.
  • Passage Guardian checks progress using AIS and/or satellite tracker at least daily, and investigates causes of off-course or stopped notifications (at any time).
  • Passage Guardian sends via email daily WMO weather forecasts for the METAREA vessel is transiting. This feature may be declined by vessel if not required.