I run large yachts for a UHNWI. We obviously wear uniform when him and his guest are onboard and when working on the yacht when he is not onboard. We always wear uniform when we are at sea or manoeuvring the yacht when "on duty". Whatever the time of day. If we are off duty we can hang out and go on deck in shorts and t shirts as that that is our "down time" and we can dress how we like. We wouldn't dream of wearing "civvies' whilst on duty. It shows respect for the job and the owner, that we wear uniform when performing our duties or are in a working environment. Saying that, when we are training, on courses or in the Sim, we don't have to wear it. But some do and some don't. All depends on your personal preference. I do because it puts me "in the mood" and sets me up to being in a "professional" mood. I am wearing the costume and so play the part. Will you act differently if you are dressed in T shirt and jeans vs full uniform..? Maybe..!