In Rockport, or any coastal area, there are allot of factors. First, you will need to look at the elevation certificate. This will be a big factor in the cost of the flood insurance. The age of the home and if it was windstorm engineered can also have an affect. Make sure there is a WPI-8 filed on the roof or you will not be able to get windstorm insurance on it. Windstorm insurance is the key because if you have a hurricane they will blame everything on the wind unless they can prove it flooded as well and then wind and flood insurance will each try and blame the damage on the other one. The short answer is it will be really expensive, but how expensive will be determined allot by the home itself