1st thing you gotta do is DRY that exposed wood...don't cover it up, seal it or NOTHIN' til it's DRY, DRY, DRY...
Then you'll want to install a sleeve thru that hole using a good marine adhesive/sealant...if were mine, I'd use 3M 4200...
Sleeves come in brass or plastic...brass would be preferred, but has to be "flared" on one end...I don't know how to do that, if it requires a tool or what...maybe somebody will come along and answer...
The plastic sleeve has a flange to cover the edge of the hole and should work fine...here ya go...
http://www.westmarine.com/webapp/wcs...key=SiteSearch
here's the brass one...description, but no picture
http://www.westmarine.com/webapp/wcs...2&classNum=698
Good luck w/it...post up some pics of the install if ya can...