The Electro Technical Officer (ETO) or Electrical Officer is a licensed member of the engine department of a merchant ship as per STCW section A-III/6 of the STCW Code and is  vital in the technical hierarchy of modern advanced ships with automated and conventional electrical and electronic systems. Unlike other marine engineers, the ETO does not carry out an assigned engine room watch and instead they generally work on a daily shift carrying out electrical and electronic maintenance, repairs, diagnosis, installations and testing.