Regarding the Mattel Sonar Sub Hunt game.
It was probably the first time a kid learned to "trash talk" during game play! Using those periscopes, you could watch as your opponent traversed your side of the board. Letting out a "I wouldn't do that if I were you!!" was common place as he neared one of your mines. That was helpful when in another turn he was about to center up on one of your subs, making ready for a depth charge! He would usually think twice.
The game used a couple of "D" batteries, that lighted the "Bug" when you received a hit on a sub. You got the ol'buzzer when you hit a mine.