A line, or a few short lines, added after the main pattern to fill gaps where coverage fell short: shoaling that narrowed the swath, a boat that wandered off line, an outer-beam dropout or an obstacle that pushed the boat wide. Infills are planned from the coverage map after the day's processing and slotted in while the boat is nearby, because a return trip costs far more than a few extra minutes.
Three small holidays along the jetty, so add infills to tomorrow's plan before we move south.
Also heard as
- infill line
- fill-in line
Related terms
Holiday
A gap in survey coverage where no data was collected, which must be filled before the survey is complete.
Coverage
The portion of the seabed actually measured or imaged by a survey, expressed as a percentage of the area.
Line plan
The set of pre-planned survey lines, with spacing and orientation, that a vessel follows to achieve the required coverage.
Mainscheme lines
The primary set of parallel survey lines that delivers the required depth coverage over a survey area.