You need sea boots.  I’ve owned a few over the years.  If you’ve got old ones (especially the Henri Lloyds) check the soles…some of them oxidize and become useless if not dangerous.  A couple of years ago I ponied up for the expensive Dubarry’s and have been happy…especially with my Grunden’s boot liners.

Here’s a link to Landfall with some other choices http://www.landfallnavigation.com/boots.html
Here they are at APS: http://www.apsltd.com/c-3777-talloffshore-boots.aspx
And here they are at pyacht: http://www.pyacht.com/dubarry-ultima-boots.htm