A kind of flags have been designed for naval battles for the time of the Civil War; those blanketed distinguishing marks for ships

https://jaredxnsc037.focalledger.com/posts/reenactment-realism-how-civil-war-flags-bring-history-to-life-2

A sort of flags had been designed for naval battles at some point of the Civil War; those integrated distinguishing marks for ships engaged in combat on rivers and seas alike.