Are you sure it's from the sea rising and not from the land sinking? I only ask because it is my understanding that there are some islands in the Pacific which, if the kind of rise you are talking about was happening, they would already be underwater. Yet they are not, or were not last time I checked. Some coastal areas can be extremely unstable and slowly sink over time, such as Venice, Italy. Even simple erosion can make it seem as though the sea level is rising when in actuality the land is being washed away. This is especially prevalent around barrier islands. Also, that area is very active geologically: lots of volcanoes and earthquakes, all of which can cause settlement of the land masses.
I'm not disputing your observations, but I should think that rising sea levels of the magnitude you are indicating would be observable worldwide and not just locally. As far as I have been able to find out there is no real evidence of any major increase in sea level. I don't deny the possibility, I just haven't seen any indisputable proof.