Astrogation
Astrogation covers the ability to use a navigation computer to gather the data on systems and planets to be travelled to and calculate a safe jump from the present location to the destination. Mostly, this is done by computer in this modern age, but there are still instances of hand calculation whenever the computers fail and the Imperial Navy and most commercial spacecraft operators require their navigators to be certified at a level to perform the linearized calculations manually, or with alternative computer assistance.
While this is not an advanced skill, Astrogation formally requires that the character take some advanced math (3D) to be able to do the first order approximations of the equations needed to calculate a jump through hyperspace. Hence, the requirements are not strict, but without the Advanced Math, the character cannot calculate a jump without a Nav Computer.