The errata states that the Explorator gets the security skill at rank 1 for 200 xp. When does he get the +10 and +20 security skills. I did not see it in the core rule book, and the errata does not say.

Which means that he doesn't get them unless you allow an elite advance.

Probably also an Errata:

I would say at rank 3 and 5 for 500xp