Maxprop wrote:
Obviously the plugs should be fairly soft, such as basswood, pine, or soft
maple (which is actually a hardwood, but a softer one). But those woods are
prone to rot, if allowed to remain damp for periods. Soak them in some sort
of oil, such as linseed, before storing them. Or you can make them from
teak, but they'll be more difficult to keep in a thru-hull after driving
them in.

Frankly, I think duct tape and a trash bag is a lot more useful than a
plug. If a seacock breaks, it is unlikely to leave a nice neat round
hole to drive a plug in. But who am I to argue with age-old tradition?

DSK