Did you know that the IDF have invented a submarine called "Shark" It's made out of 26% shark skin mixed with Zinc and Manganese dioxide, the rest of the submarine is titanium, anyway what is so special about this submarine? You can't detect it on radar. Well that's a bit misleading... You can detect it on the radar but you wont see a submarine, you will see a shark. The design and shape of the submarine is indistinguishable from a real shark making it blend in with all the other sharks. The IDF have additionally hired a team of professional painters for each submarine making each one is unique. How would you respond if you saw a shark on a radar? Exactly you wont, you would ignore it and next thing you know it you are blown to pieces