While economical transit makes sense for civilian (commercial) vessels, a naval ship is not always followed by a fleet oiler. Having all four gas turbines online at all times probably does not count as “economic cruise”.
[quote=“Steamer, post:645, topic:45129, full:true”]How many merchant ships keep all the generators online and synched with the shaft generator at all times?[/quote]
I’ve seen a diesel-electric vessel sailing with multiple 1990s era gensets online at 20-30% load for ten days straight. I found it rather surprising but the engineering folks said it was ok with the fuel they were using.