This is one of those old quirks that have existed since SH3. Or rather, it's an unresolved bug or feature (take your pick), that has existed in SH3, carried over into SH4, and also SH5 since it's based on the previous two games.
Periscope up = watch officer calling out visual contacts since the periscope counts as a visual sensor.
Speaking of sensors, you only have one active sensor available at a time. Say for instance yourr looking at your map and looking at all the sonar contact lines of an incoming convoy. Raise your periscope and the contact lines go away, because the game went from using the hydrophone sensor, to the visual sensor. Drop the scope, wait a second or three, and the contact lines will reappear. At least thats how SH3 and 4 behave in this regard, so I'm assuming 5 does as well.
|