…also, for what it’s worth in addressing the question, here is the actual experience of my great-grandfather enlisting in the Union Navy underage and serving in battle. This comes from his civil war pension document, sworn before an attorney in 1909.
He and a friend, ages 17, living in Boston and going to “high school” (as he stated it in 1909), dared one another to enlist. Young James Fink was bold enough to try. Getting wind of this, his long-suffering father “posted” him at all the recruiting stations in the area, so he ran away to New York City, “having gotten the idea to enlist into my head.”
In New York (in late august of 1864, I believe), soon out of money, hungry and without shelter, he saw a tent in “a park” and took shelter in it for the night, though it was full of “a lot of rough looking characters.” In the morning, an Army recruiter threw open the flap and loudly asked, “Good morning, boys, sleep well?” offering to buy breakfast for any man who would enlist. James Fink took him up on it.
Over breakfast, Fink told the recruiter he wanted to join, but was underage and posted in Boston by his father–whom he expected was now on his trail (correctly). The recruiter took young Fink over to New Jersey and enlisted him in the Navy, with the lie that he was German-born (his parents were German born, he was born in Boston). The reasoning was that Nativist feeling of the time and manpower needs made it more likely he would not be questioned too closely, he says in his pension document.
He served on two ships, the first on blockade duty off Southern coasts before he was transferred to a “modern” screw frigate that was the flagship of an amphibious force that made two assaults on Fort Fisher, North Carolina, covering the last open port of the Confederacy at Wilmington. The first battle was a farce that went nowhere. With new leadership the second battle was a hot and bloody affair. Young Fink was a “powder monkey,” carrying up from the magazine deep in the ship measured powder charges sewn up in burlap, dropping them off at guns engaged in action. At one point, he held two bags in front of his face as cover from “a coming shell,” and hearing laughter, looked up to see the ship’s captain laughing at him, at which, realizing the absurdity of it, he laughed, too, he says in this sworn document. He mentions a man named “Cushing” or “Cushman,” (getting the name slightly wrong, as I recall) a historical figure during the battle who made a deep impression on him for his fiery leadership.
His ship lost it’s mizzen mast, and they were “pretty badly shot up.” They put into a Navy base at Boston, and father showed up with discharge papers he said came from the secretary of the navy (Fink admits he never saw those papers, but he was discharged from the Navy, with paperwork done aboard ship, and taken home by his father). His discharge papers (which I have seen) say, “ship’s boy, discharged, underage.”
Maybe this helps answer your question a bit.