No Lt Commanders?
I found the rank structure of the ship a bit odd. We have the Captain, a Captain, the executive officer, a Commander, and a host of Lieutenants. Nothing strange there. However, there were no Lt Commanders. This doesn't seem conventional.
In case you were thinking, well, there probably were, we just didn't meet the characters, no, there were no Lt Commanders at all. When Commander Quigley is promoted to command his own ship, MacDougall, a Lieutenant, becomes executive officer. If there was a Lt Commander on board, he would have become exec officer.
Like a bird on the wire, like a drunk in a midnight choir, I have tried in my way to be free