HC, I don't think you are giving it enough credit. 212man is maintaining an obstacle (and rig) database as a user waypoint instead of an EGPWS database. By describing the user waypoint as an "airport" when he enters it, it then displays on the map screen. He now has an obstacle database that displays on a map view and can be controlled on his base. It can be updated every night, or even during a flight if he receives updated information while enroute. In reality, most rigs are anchored to the ocean floor and don't move too often, so it is only the few exceptions that need to be addressed on a day-to-day basis. The radar will still work well below 2000' to provide obstacle avoidance of things like aircraft carriers and crane barges that poke up a long ways and are not part of the offshore operations.
Pretty close to reality I'd say. Not even EVS will do what you are looking for. AVAD is supplementary to old aircraft configurations that had nothing. It is an old technology now superceded by EGPWS. Reminds me of the North Sea fascination with keeping the old King 90 GPS units alive because they had invested so much into them.
malabo