[...]
11 In this Division,
(d) the corrected margin line, if the actual margin line either forward or aft is not of ordinary parabolic formFootnote * or if its lowest point is not at amidships, a margin line of ordinary parabolic form shall be drawn with its apex amidships level with the lowest point of the actual margin line, and intersecting the latter either at a point one quarter of the ship’s length from amidships or at the perpendicular according as the actual sheer at the perpendicular is respectively greater or less than four times the actual sheer at the one-quarter length position, (see Fig. A in this Schedule);
(4) Where a crew access opening described in subsection (3) is located on a raised portion of the main deck extending aft not more than three-quarters of the length of the ship, the height of its door-sill or coaming may
(a) in the case of a door-sill or coaming located in the part of the forward half-length of the ship not in the bow section, be reduced by 460 mm or an amount equal to one-quarter of the vertical distance between the freeboard plane and the upper surface of the deck outside the mid-point of the opening, whichever is the lesser;
100 In this Part,
bow section means the foremost
(c) one-quarter length of a ship, in the case of a ship 21.35 m in length or over; (partie avant)
