[C-Wolf]

Both sets of commands are used in the real world depending on the situation.

In most cases, speed commands directly from the engine order telegraph (I know, weird name) on the Helm are conveyed to Maneuvering for action by the sailor manning the Throttleman watchstation.

The Conn commands, "Helm, Ahead One-Third" which generates a reply of, "Ahead One-Third, Helm Aye" followed by execution of the order. The engine order telegraph on the helm is switched to, "AHEAD 1/3" and Manuvering acknowledges the order by moving their repeater to "Ahead 1/3". At that point, the helm reports, "Manuvering answers Ahead One Third", followed by the Conn responding, "Conn, aye."

If the Conn wants a specific speed, --say to match a contact when trailing, then they'll order, "Manuvering, make turns for eighteen knots" within the proper region that would be covered by the ordered EOT setting. The Throttleman regulate the ship's engines to produce the proper revs equating to the requested speed. Maneuvering will answer via the 7MC, (Engineering circuit) "Make turns for eighteen knots" Maneuvering Aye".

Every verbal command is repeated on a submarine in an effort to avoid mistakes.

During a TRAILEX --or the real deal, there is a well-synchronized, verbal ballet of constant comms between the Conn, Helm, and Manuvering. Ordered speed, course, and depth have to be properly ordered and instantly executed with no room for error. The OOD on the Conn is in charge, and the Diving Officer sitting behind the helm ensures his orders are understood and carried out. The Chief of the Watch sits at the BCP (Ballast Control Panel) controlling trim and setting line-ups for certain evolutions, while the Helmsman, (--probably the most boring watch station on the boat, manned by the most junior crewman) control depth and course.

Obligatory Sea Story #1: We had an Air Force general onboard for sea trials once. After an emergency blow demo followed by high-speed maneuvers complete with snap rolls, (like an aircraft, so he could relate) he stood next to the helmsman watching all of this unfold, and asked about their training. When the Diving Officer explained, "These are eighteen year-old guys who never attended anything other than mandatory submarine school and don't have regular jobs on the ship yet, since they're the most junior. We plant them here until they figure out what they want to do in life."

The General's face went slack and the color drained from his face. He was speechless. It was pretty funny to watch the expression on his face as the Dive's explanation sunk in, since he sort of equated them to pilots flying a high-performance underwater aircraft, with their control stations arranged the way they were. . .

Obligatory Sea Story #2: As explained, the helmsman/planesman are two of the most junior enlisted watch-standers. The Diving Officer is one of the more junior officers as well.

From the mouth of babes: Once upon a watch, the bay-faced helmsman says to the equally peach-fuzzed-faced D.O. sitting behind him, "Sir, you can write me up for what I say, but not what I think, right?" To which the young ensign replies, "Uh . . yeah."

Everyone in the front of the Control room was intently listening now, trying to figure where this was going. . .

Without skipping a beat the Seaman recruit says, "Sir, I think you're ****ed-up." Everyone within earshot doubled-up in side-splitting laughter, while the poor Ensign was powerless to respond. An epic classic boring watch story was born and spread through the boat faster than a headcold.