Section 179.310 - Collision bulkheads(a) Each collision bulkhead required by § 179.210 , must be constructed in accordance with § 179.320 , except that a collision bulkhead: (1) Must extend to the weather deck or to one deck above the bulkhead deck, whichever is lower, for service on oceans or coastwise routes; and(2) Must not be fitted with any type of penetration or opening except penetrations may be made if they are located as high and as far inboard as practicable and they have a means to make them watertight.(b) The forward collision bulkhead required to be on a vessel by § 179.210 must be: (1) Located at least 5 percent but not more than 15 percent of the length between perpendiculars (LBP) aft of the forward perpendicular, or for vessels with bulbous bows extending forward of the forward perpendicular and contributing more than 2 percent of the underwater volume of the vessel, located at least 5 percent but not more than 15 percent of the LBP aft of the mid-length of such extension; and(2) Installed in a single plane, with no recess or step, up to the bulkhead deck;(c) The after collision bulkhead on a double-ended ferry of more than 19.8 meters (65 feet) in length must be: (1) At least 5 percent but not more than 15 percent of the LBP forward of the after perpendicular; and(2) Installed in a single plane, with no recess or step, at least up to the bulkhead deck.