Surface Navigation Skill for a Hiveworld Scum

By Aresay, in Dark Heresy Rules Questions

Hey guys,



If a scumer picked Navigation (Surface) as a skill in your game, would you let them use the nav skill underground in a hive or forgeworld?

For instance, if the group were heading down/up in a hiveworld and the scummer headed to the local arbitrator office and requisitioned a map of the different levels of the hive and while the group was down there, could the said scummer use the nav skill and map/s down there to give more precise directions?

Just something that poped up when rolling for a character.

Cheers,
Aresay.