Why There Are Holes

Transparent patches on a satellite pass are real coverage gaps (cloud, sun glint, the edge of the satellite's swath, or land), not a bug. The satellite genuinely couldn't get a reading there, and the map shows that honestly instead of filling it in.

What causes a hole

A satellite pass can miss a reading at a given point for a few reasons: cloud cover blocking the sensor, sun glint (reflected sunlight overwhelming the reading), the point falling outside that orbit's swath on this particular pass, or the point simply being land rather than ocean. Land itself is masked out visually with its own overlay on the map, separate from the ocean data layer.

What the map tells you when you click a hole

The underlying data doesn't distinguish cloud from land from a swath edge: all three are stored the same way, as a missing value. What the click readout does tell you is what kind of layer you're looking at: click a hole in a satellite pass and the popup reads "No usable data"; click a gap in a composite and it reads "No data (gap)" instead. See passes vs. composites for what that distinction means for freshness and coverage.

How the timeline shows holes at a glance

You don't have to click around to know a pass is mostly holes. A cloud icon appears on any timeline pill where 95% or more of the pass has no usable reading, so you can skip it without opening it. See using the timeline for the rest of what the timeline icons mean.

Why we don't fill holes in

Filling a hole means guessing at data that was never actually observed: that's exactly what a daily composite does, and it's labeled as a modeled estimate for that reason. A raw pass stays raw. If you want a complete, gap-free picture instead of real holes, switch to the composite for that layer, or check pricing for which tier gets you both.