Lookout never really seemed to be one of the requirements on the P-3 - once caught a periscope (and ECM mast) almost directly underneath a P-3 which was at 2000ft as we came in at 200 ft to relieve him on task, just as he finished telling us the area was clear. He seemed a bit miffed as we called in Certsub and exercise kill at the same time.
Presumably this (lack of lookout requirement) has carried over to the P-8.