Section 31(b) in The Merchant Shipping (Examination Of Engineers In The Merchant) Navy Rules, 1963
(b)in the case of a candidate for a First Class Certificate, the service has been performed in lake or river steam vessels of not less than 99 nominal horse-power and/or motor vessels of not less than 560 brake horse-power, and the candidate has had, in addition to his lake or river service [*] [The conditions under which sea service must be performed in order to count towards the qualifying periods for Second and First Class Certificate are set out in rule 15 et. seq.], at least six months' qualifying service' at sea in a foreign-going ship or the equivalent service in the home trade.
