Global Fishing Watch believes in the power of sharing meaningful data publicly and freely. Because anyone around the world may be using and sharing Global Fishing Watch data on vessel identity, location, estimated events, and associated registry records publicly, we must ensure this public output is of the highest confidence and also the most conservative estimates of vessel activity.
Our analysts and researchers have access to additional data that requires more detailed review, inspection, and regional knowledge that may produce different results than those shown on the map. For example, because we know automatic identification system (AIS) transmissions may not always be consistent, we have developed two levels of confidence in our estimates of vessel voyages:
- Confidence level 4: we see the full activity of a vessel entering and exiting the port, shown in the public Global Fishing Watch platform and through the Global Fishing Watch data download portal.
- Lower confidence levels: We may only see a partial port visit (it may appear and leave port, but we may not have seen it enter port).
A Global Fishing Watch analyst familiar with the vessel activity they are researching may choose to use and document analysis using the lower-confidence voyages and, therefore, may see more possible activity by the vessel. However, in our public products like the Global Fishing Watch map or public APIs, for all users, we must ensure higher confidence in the data we are sharing to aid in the correct interpretation of vessel activity to the best of our abilities.
If you are interested in lower-confidence voyage data, please contact us at [email protected] so we can update our roadmaps accordingly.