Haze gray and underway is a United States Navy saying that refers to surface ships in arduous duty at sea, in contrast to submarines or naval units in ceremonial roles or in port.
Haze gray is a paint color scheme used by USN warships to make the ships harder to see clearly.
[5][6][7] Secondly, "underway", as opposed to being anchored, docked, alongside, moored, or otherwise attached to a fixed place.
Thus, "haze gray and underway" is shorthand for naval surface warships at sea.
It is also used to refer to life in a vessel at sea with the working Navy, as opposed to shore postings.