Another option is to replace with Beckson.
I used Rain Drains. Same size as my original Grays. The water drains are a little further out toward the edges but close enough. The gaskets are better and they only have two levers that flip to open. Much faster. Same price. And that is negotiable too because Beckson is in all the marine stores. Go here,http://www.beckson.com/ Go to my web site to see them on my Hunter. There are peeks, before and after.