Usually, watch team is composed of two or well trained persons. For the future, domestic shipping industry will be short of crew resources But it takes a long times to educate watch keeping practice for crews. Herewith, we could achieve one person bridge operation (OPBO) systems more safely and comfortably compared to traditional dual watch system, then we could sustain activities in domestic industry and manage to trade off reasonable safety and productivity. For this purposes, we have developped the system which has ability of more than dual persons, and demonstrated OPBO system on board which is physically and mentally comfortable. The main human machine interface is in usage of the voice control input/output equipment. This paper writes the OPBO system in brief and evaluates the results of physical and mental aspect during sole watchkeeping and.also analyzees the performance of some sole and dual persons' watchkeeping standards.