The rules reference card, "Using Bombs" that came with the Scurgg expansion indicates, that if a bomb is placed overlapping a ship's base then the bomb token is placed under the ship base and does not detonate immediately.
The rules reference book that comes with the newest core set indicates a bomb token placed overlapping a ship base does detonate immediately if the bomb is normally triggered by a ship or maneuver template being placed over it.
There is nothing in the current FAQ addressing when a contact mine detonates. There is mention of it in an FAQ several years ago but the verbiage has since been removed.
So because the rules reference card from the Scurgg expansion is the most up to date rules document, with no clarification in the current FAQ, does the reference card have precedence? Meaning mines no longer detonate immediately if placed under a ship base.