I have worked primarily as chief engineer or electrician on commercial fishing vessels, mostly in the Bering Sea. Generally it's 12 hour shifts, and the boat is in continuous 24 hour operation. Typically, systems that require simultaneous engineer attention include fishing hydraulics, power generation, processing equipment, propulsion, & refrigeration. When I first come to a new boat, I have these issues when I'm switching between these things. As time goes on, I develop a mental model of the specifics of the entire vessel, and instead of switching between different things, I'm paying attention to one, more complex thing. When that happens I lose this penalty somewhat. The problem comes when returning from vacation, because I want to enjoy the loss of penalty, but the model may no longer be complete or may be intermixed with models of other vessels.