I bought the boat without a head. If I do plan on using the head, I'll just bring a porta-potty. What kind of plug should I get and where would I find a plug? You asked "Why do you want to do it?".... simply because I'm not currently using the thru-hulls and I just want my boat to be safe on the water and at her mooring. The boat is a 20ft, full keel daysailer. Thanks for your help Peggie! Bob Melanson ******************************** Response to Need to seal my thru hulls..... any suggestions?: Head removed for legal reasons? Submitted by Peggie Hall/HeadMistress on 06/12 at 11:07AM regarding Hunter Corinthian There's no legal reason whatever to remove a toilet, only to secure it against direct overboard discharge...which can be as simple as closing the seacock and removing handle, or if you're NEVER gonna use it, just removing the head discharge hose altogether. If you're sure you'll never want to install another toilet, and if you're absolutely certain that you'll keep this boat for more than a 2-3 years, the best thing to do is remove the thru-hulls and glass over the holes. Otherwise, put plugs in 'em, close the seacocks and remove the handles, and attach and secure a length of hose to each one that's well above the waterline in case the plug fails. But before you do anything...WHY do you want to do it? What size is the boat?