153. When any person subject to this Ordinance has been convicted by a naval tribunal of any offence, the Government, the Chief of Naval Staff, or any officer not below the rank of captain empowered in this behalf by the Chief of Naval Staff may,(i) either without conditions or upon any conditions which the person sentenced accepts, pardon the person, or remit the whole or any part of the punishment awarded, or(ii) mitigate the punishment awarded, or commute such punishment for any less punishment or punishments mentioned in this Ordinance:Provided that a sentence of imprisonment shall not be commuted for a sentence of detention for a term exceeding the term of imprisonment awarded by the court.