If your trying to find something thats flood resistent good luck. Best advice buy good flood insurance

Be thankful it's your beach house and not your primary dwelling, or am I assuming wrong here?

Heck...you could carpet the whole thing and then rip it out and replace it with each flood. After all, carpet is dirt cheap compared with other flooring options. Or maybe painted exterior plywood?

I am incredibly lucky that this was just a vacation home, although we are now under water literally and figuratively. And I do have flood insurance but the amounts available are limited by the government and it is not possible to get replacement cost flood insurance for a secondary home.

I am leaning toward glennsfc's suggestion to just stay with carpet. It makes it easier to rip out and replace subfloors, too.