37. Passenger ships which are not required to be subdivided shall be marked on the side amidships with the freeboard assigned in accordance with paragraph 2 of Section 3 of Schedule 2 in Merchant Shipping Notice MSN (1699(M). The mark shall consist of a horizontal line 25 millimetres in breadth and 300 millimetres in length. The colour and method of marking shall be in accordance with regulation 36.