Blood Is Blue When It's In Your Veins!
Incorrect, no matter what someone claims about it being "deoxygenated." Our blood is always red, according to doctors and horror movies. It just sometimes looks blue through our skin because of light scattering.
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.