We have been researching and planning for three years to get ready to start construction on our vacation rental in Bradenton, Florida in a few weeks. I had to take a crash course in FEMA flood zone regulations, The Biggers / Waters act with the subsequent removal of government subsidies flood insurance industry, the 50% rule and the new face of available flood insurance in Florida. Plans went from planning a renovation of the existing house on the ground, to finding a contractor and building a new elevated house.
Bottom line, if you own a second home or vacation rental in Florida and it is below the base flood elevation as defined by the FEMA flood maps for your area, you will spend a large amount of money each year for flood insurance through the federal program (if it is your primary residence, your get a huge break on the insurance but I don't think that will last forever). There are some independent insurance companies backed by Lloyds of London that are reasonable and much less. We are building our home elevated above the BFE, so our insurance is a fraction of that cost with a standard insurance company. All lenders require a flood insurance policy for the duration of the loan.