Jacket and case manufacture. 1  3 The jackets of the 8-inch and 5 1/4-inch disks are cut out of polyvinyl chloride (PVC) stock to appropriate size, and the fabric liners laminated to them. 2  4 The case or shell of 3 1/2-inch disks is molded out of hard plastic.
Aft: generally anything astern of the z-axis mid-line of a vessel; diminutive of the word after. Bow: the forward section (or fore) of a ship. Stern: the rear section (or aft) of a ship. Port (side): the left side of a ship from the perspective of a person standing on board and facing the bow of the ship on the bridge. Starboard: the right side of a ship from the perspective of a person standing on board and facing the bow of the ship on the bridge.
Port and starboard are nautical terms for left and right, respectively. Port is the left-hand side of or direction from a vessel, facing forward. Starboard is the right-hand side, facing forward. Since port and starboard never change, they are unambiguous references that are not relative to the observer. The term starboard derives from the Old English steorbord, meaning the side on which the ship is steered. Before ships had rudders on their centrelines, they were steered with a steering oar at the stern of the ship and, because more people are right-handed, on the right-hand side of it.