EL02.jpg [2/15] Author: J. Stormer Source: 050530PPJS Copyright: 2005 J. Stormer Credit: J. Stormer Caption: This is a Marelon™ seacock made of fiber-reinforced nylon. Although it is "plastic", it is much stronger than PVC and other common plastics. A tapered wooden plug is tied to this seacock. The plug is to be used if the seacock fails or breaks. These plugs of appropriate size should be secured near the thru-hull where they can easily be found.