Notes:
According to the IPCC's 2007 predictions, potential sea level rise by 2100 is less than 1 meter, but it's a controversial subject and estimates of 5m and even higher have support in the scientific community.

This mapplet's analysis suffers from the shortcomings described in a series of posts at Free Geography Tools (1 2 3 4 5 6 7), specifically that the data's resolution is too low for accurate small-scale predictions, and that we are not taking into account whether ocean water can actually reach a particular location.

For simulations that don't suffer the same shortcomings, visit the Free Geography Tools URLs listed above, which also show flooded buildings, and Architecture2030, which shows the results of accurate predictions for over a hundred US coastal cities.

The data's vertical resolution is one meter, so threshholds you enter will be rounded to the nearest meter. In particular, if using English units you'll find your entry rounded to 0, 3, 7, 10, 13, ...

A similar non-mapplet app can be found at Flood Maps.