Section 328(1)(a) in The Merchant Shipping Act, 1958
(a)any such certificate may be issued in respect of any such ship as in respect of an Indian ship provided that [any such certificate issued in respect of a ship carrying cargo or passengers being an existing ship of one hundred and fifty tons gross or more or being a new ship of twenty-four metres or more in length] [[ Substituted by Act 25 of 1970, Section 14, for certain words (w.r.e.f.21.7.1968).]] and registered in a country to which the Load Line Convention applies, shall only be valid so long as the ship is not plying on voyages from or to any port in India to or from any place outside India and shall be endorsed with a statement to that effect and shall be cancelled by the Central Government if it has reason to believe that the ship is so plying; and