Question: When can you as officer of the watch use the vessel’s engines?
Answer: The vessel’s engines are at your disposal as the OOW, and there should be no hesitation in using them in case of need. Where possible, timely notice of intended variations of engine speed should be given to the duty engineer.
Note– As OOW you should know the handling characteristics of the vessel, including its stopping distance, and should appreciate that other vessels may have different handling
A reminder- Rule 8 States:
(e) If necessary to avoid collision or allow more time to assess the situation, a vessel shall slacken her speed or take all way off by stopping or reversing her means of propulsion.