The freeboard mark referred to above should measure 300mm
in length and 25mm in depth. The marking should be permanent and painted
black on a light background or in white or yellow on a dark background.
The top of the mark should be positioned at the waterline corresponding
to the draught given in Section 12.1.1, at the position of the longitudinal
centre of flotation, as shown in the sketch below:-
A vessel should not operate in any
condition which will result in its freeboard marks being totally submerged
when it is at rest and upright in calm sea water.
Sailing
vessels with variable ballast are to be specially considered by the
Administration.