In the Keys, flood insurence starts when the homes floor gets wet. In my case the floor was 10 ft off the ground,, meaning we will never be able to collect unless there is a 30-40 ft serge,, ant gonna happen...
BUT you can't get a mortgage with out it,, and separate wind storm coverage..
In the 16 yrs we lived in the Keys, We had 13 named storms hit our little rock, two cat 1, one cat 3. With the acceptation of USAA coverage,, all the insurance companies, including the government, were weeks/months in paying.
Most of our friends hired lawyers that specialized in ligating federal insurance claims.. These "ambulance" chasers got more than fair percentages of the settled claims...