Sea levels ARE rising, just not very much, not very fast, and it’s not worth worrying about at the moment (much less disrupting the economy). But to effectively argue with the global warming zealots, you need to bring as many facts to the table as you can, so the site seems useful.
No, they are not. For the overall sea level to 'rise' would require VAST amounts of water. Where would that water be coming from ? The amount of water on the planet Earth has not changed significantly for millions of years, if not billions of years.
HOWEVER, the GROUND moves up and down CONSTANTLY.