This common idea of "I'm not required to have flood insurance so I don't" is so weird and misplaced. You're not required to have comprehensive auto insurance (collision) but anyone who can afford it has it because it's foolish not to. There are some pretty obvious examples of insurance that people get as long as they can afford it . . . even though its not required by any authority.
The house is usually the most valuable asset to people - why on earth they would simply go uninsured against a reasonably foreseeable risk (you live in a hurricane zone!) simply because it's not "required" - it's so strange and foolish.
I'm in flood zone X and not required to have it. But I'm about half a mile from the Charleston harbor and five miles from the Atlantic Ocean. Not having flood insurance would be asinine.