In the 2D Line View line selection box, lines are organized by survey name, which is left-justified. Line names are indented below the survey name, and they are sorted in alphanumerical order. It is possible to load duplicate 2D line names to a project associated with different surveys, if this happens you can use the left-justified survey name at the top of the line list to differentiate the line names.

As well as the trace data displaying in the view, the Line selection box will be drawn with a solid grey colour when you select a survey line name with traces present in the active displayed volume in the display.

Here the line B89-18M has associated trace data in volume B89_NE_Survey_4s8b. Trace data appears in the view and the Line selection box draws with a solid grey outline indicating this is so.

The line selection box can also be displayed with a dashed red or dashed grey outline to indicate a mismatch between the selected line and the displayed volume.

If you select a line name which does not have traces in the active displayed volume, no trace data will be displayed in the view and you will see a dashed grey outline around the line selection box indicating that the volume data does not exist for that line selection.

Here Survey_B89_NE is not associated with volume GPCT93_NE_Survey_4s8b and so Line name B89-18M does not exist in volume GPCT93_NE_Survey_4s8b and there is no associated trace data. No data is displayed, and the Line selection box is drawn with a dashed grey outline. The volume must be changed to match the survey selection for traces to be displayed and the line selection box outline to become a solid grey line again.

Here, volume B89_NE_Survey_4s8b is associated to Survey_B89_NE, but the Line name B89-22MA does not have any traces loaded to volume B89_NE_Survey_4s8b and so no data is displayed. If the SEGY data can be located and loaded for line B89-22MA, the volume can be displayed and the line selection box outline to become a solid grey line again. 

The dashed red box outlining a line selection means that you've selected a line name which exists in the displayed volume, but you've selected it from a different survey to the one associated to the volume. This happens when the same 2D line has been loaded to multiple surveys creating duplicate line names.

In this example two surveys are available, Survey_B89_NE and 2d_regional_ALL. The line name B89-18M is duplicated and exists in both surveys. Using the search filter in the line name box it is possible to see the line listed in both surveys.

The active displayed volume in the 2D line view is B89_NE_Survey_4s8b and is associated to Survey_B89_NE, not 2d_regional_ALL.

Selecting line B89-18M from Survey_B89_NE displays the trace data as expected and draws the line selection box with a solid grey colour indicating a survey - volume match.

Selecting line B89-18M from 2d_regional_ALL  displays the trace data but draws the line selection box with a dashed red colour indicating that the line selected is part of a different survey from the display volume. Trace data is still displayed because the line name and navigation information is duplicated and available in the active displayed volume.

Interpreting on a volume when the line selection outline is dashed red will store horizon picks with another survey to the one intended and can cause confusion and problems in the future. Avoid interpreting horizons when the line selection box is red unless you have good reason to do so.

To make sure you’re displaying the correct data, always check you’ve selected your line from the survey associated with the displayed volume.