Guide
How to read the map: age, grid size and estimates
Ocean data come from satellites and models that were built to answer different questions. Gannet View keeps four things apart for every layer so you can judge what you are looking at.
Source resolution
The finest detail the provider's data contains. A 9 km model cannot show a feature one kilometre wide, however it is drawn.
Displayed resolution
What the map draws at the zoom you are on. A wide view takes fewer points than a close one, but never invents detail the source does not have.
Observation age
How old the newest reading is. A satellite sees the sea on a pass, and the data arrive a day or more later. The map shows the age and says when a day is held or forecast.
Refresh
How often we rebuild the layer from the provider. Rebuilding often does not make the underlying observation newer.
Estimate or measurement
Where cloud hid the water, the map fills the gap and draws it faded or dotted, so a guess is never drawn like a measurement.
Gannet View shows conditions. It does not tell you where fish are.