Tapping A Can Of Soda Stops It From Exploding When You Open It!
If you believe this, you are so(da) wrong. Tapping the side of a soda can before opening it doesn't do anything. In fact, it only agitates the soda more. And agitated soda is dangerous soda.
So what you're saying is that you always have to go when around jellyfish.
radar DOES NOT DEPEND on sight - you dont "see" except on your screen - radar is based on "sound" NOT "sight" - day or night - radar works.