> how is it possible that they are not able to find / detect it ?
The ocean is a very large thing, especially when it needs to be searched in three dimensions.
The ocean is a very large thing, especially when it needs to be searched in three dimensions.
This is definitely the big snag people lose themselves on. They are thinking about the search being in two dimensions, like a map. They aren't thinking about lost ships or planes in three dimensions; a formula squared vs. a formula cubed and how much faster the latter gets out of hand.
But irrelevant to the point. Submarines are designed to be hard to find in an environment which very nature already makes things hard to find due to there being so much "stuff" in the way