The most common reasons for not receiving responses for some of the vessels that belong to your fleets are:
Incorrect or No use of the timespan
- The API returns responses based on whether the information about a vessel was received during the defined /timespan:{value}/. If the timespan is not defined (default values is used) or is smaller than the time the AIS message was received then it is not contained in the API response.
Insufficient Credits
- there are not enough Credits in your account for the API call to go through.
No terrestrial coverage in the area
- some of the vessels of your fleets may sail in areas with limited coverage from terrestrial AIS-receiving Stations. Consider upgrading your service to also include satellite coverage.
The actions mentioned are applicable to the following API Services:
PS02 - Vessel Positions of a Static Fleet
PS03 - Vessel Positions of a Dynamic Fleet
PS06 - Vessel Positions in a Custom Area
VI01 - Voyage Forecasts