VL_end is an analysis export variable.
It reports the distance (measured by vessel log) from the first ping in the analyzed variable to the last ping in the domain which was analyzed.
This variable is exported only if it is selected on the Export page of the EV File Properties dialog box.
About analysis
About analysis variables
About ping position
About VL_Mid
About VL_Start
About Dist_E
About Dist_M
About Dist_S