I don't know that you are any less likely to get a mortgage, but your annual insurance bill could end up being exhorbitant. If you are in a flood zone you would be required to get flood insurance by your mortgage company. There are three parts to insurance coverage in a flood zone in Florida: 1) Hazard (your typical policy that covers theft, fire, etc. 2) Wind, which makes up only part of your hurricane protetction and 3) Flood, which covers you in an event of a regular flood or hurricane-caused storm surge.
The wind portion of Florida policies is what has gotten so out of control in the past three years. If you hear of people paying $4000, $5000 or more a year on insurance, it's a good bet that at least three quarters of that is for the wind policy. The insurance companies have come to the realization that even those who live inland in the path of a hurricane are vulnerable to damage, so they are charging people so much that for many it has become an economic hardship. Total policies that were once a managable $1,000 a year have tripled or quadrupled, and the wind portion is the reason why.
Flood insurance is another animal entirely. The vast majority of policies are backed by FEMA (even if they are sold by individual companies, they are guaranteed by the government). If you are NOT in a flood zone, the standard rate is $317 a year for $250K worth of coverage. Many people, like me, buy flood insurance even if they aren't in a flood zone just in case a major hurricane causes a huge storm surge that wipes out our house. (If that happened, wind coverage would not help us.) It is not much to pay for peace of mind.
There has been almost no media coverage about flood insurance rates, so I don't know if the government has raised its rates -- or plans to -- in the face of more hurricane-related vulnerability. I found this link where you can estimate your premium costs (remember: flood insurance only) if you know the zone of the property you are interested in:
http://www.floodsmart.gov/floodsmart/pages/premiumest.jsp;jsessionid=659761E777FE4A06494D6C44F3EA076
I don't know what happens if half of your lot is X and half of your lot is something else. Maybe if you can build entirely on the X portion you would get the X price. You need professional advice for that question, or maybe someone here knows.
My point after this long-winded spiel is not only would your precious beach house be more vulnerable to hurricane activity, the carrying costs in a flood zone might be too high. Because no matter what, you are going to get hit with a high wind premium.
