Action_Carl said:
"Navigators are mutants of a very special kind, and although their appearance can vary a great deal they always have the power to navigate through warp space. Although this is a psychic ability, navigators never have other psychic powers and are no more vulnerable to psychically attuned warp creatures than any normal human ." (pg 150)
Is this because of the rules or because that is the way they wanted the background? One of my reasons for wanting navigators to be psykers is because it sounds logical. If the Astronmicon sends out a psykic signal then you have to be a psyker to hear it. Psykers are psykers. The other reason is because of the rules. With psykic powers a navigator has another asset when it comes to regular adventuring and a place to fill in a party.
I can agree that it sounds risky to have the navigator to tag along if there is only one on the ship but I am sure that can be solved. Military vessels also have one navigator and the risk of dying on the ground can't be that much bigger compared to die in a spacebattle. Anywat even if it is, then military vessels must have a backup plan.