Ship: As those outside of Noe's Ark were destroyed, the ship became a perfect early symbol of the Church with its associations with "the barque of Peter, the Fisherman." In the same vein, the main part of a church's interior, the place where the people worship, is called a "nave," from the Latin "navis" -- ship. The Ark is also a symbol of the Temple through its shape and purpose, both having three levels, etc. And as a symbol of the Temple and Church, it is a symbol of Mary, sealed off with pitch and closed up by God Himself.