I like to write in my free time, and I'm taking creative writing next semester. I'm pretty excited.
My main influences are Star Trek, Battlestar Galactica, Babylon 5, Starship Troopers (the book, not the awful movie), Halo, and
The Lost Fleet. My story combines a bunch of concepts from these sources, but incorporates a number of original ideas I've had w/r/t the primary story line.
(If you have even a
passing interest in military sci-fi, you owe it to yourself to pick up The Lost Fleet. It's probably the best military SF I've ever read.)
That said, I've been working on this short story but I'm looking some information about the rank structure onboard naval ships.
Obviously there is a captain and an XO. An XO typically holds the rank of Commander or Lt. Commander, correct? Also, is it unusual for captains of smaller ships (destroyers? frigates?) to be Commanders?
This is where it gets a little fuzzy for me. In Star Trek, the senior bridge officers typically consist of tactical, operations, helm. Communications, and Ops is usually a lieutenant or a lieutenant commander (Sulu or Data), Tactical is usually a lieutenant (Worf, or Sulu again), and helm is usually an ensign (Chekov or W. Crusher). But, I know that Star Trek is by no means an accurate representation of a real-world rank structure. Among other things, there's only been one enlisted crewman seen throughout the entirety of the
franchise 
So that brings me to BSG, which is closer to replicating a naval ship. The rank structure is more flexible. But in BSG we learn very little about the rest of the bridge crew. There's a Commander and an XO. (Galactica's ranks are differently named than real world naval ranks, the CO is a Commander and the XO is a Major. It's also bigger - Commander is the highest non-flag officer but is an O-8, not an O-6). Past that, the rest of the crewmen on the bridge are enlisted and the only one who we ever really learn about is the comm officer who is is an E-5 (and she's later promoted to an O-2).
The bridge structure is similar in The Lost Fleet. Both main characters hold the rank of Captain. One commands the fleet while the other commands the flagship, which the fleet commander operates on. (He isn't an admiral because the admiral was killed in the opening chapter and he is the most senior captain by date of rank.) The rest of the bridge officers are only ever referred to watch standers. No ranks, no names. Hell, we don't even learn about an XO.
The only reference I have is Star Trek but I know that it can't be particularly accurate. I don't want to have the bridge crew be nameless, though. I'd prefer to have more characters to work with. (One of the few nitpicks I have with The Lost Fleet is that there are only three central characters; two Captains and a civilian. The most prominent secondary characters are the captains of the other ships in the fleet. Like I said earlier there's yet to be any mention of the XO on the flagship.) So, basically, what other officers/crewmen would typically be on the bridge? Is there a weapons officer? A communications officer? Are they enlisted or are they officers? As far as shifts go, how many crewman would there be that fill the same role?
So that covers my questions about rank structure. Next up: physics.
One of the things I really like about The Lost Fleet is that it's the only sci-fi story I've ever read that really takes relativity into account. All distances are measured in light-minutes/hours/days/years, not km, because using lightspeed as a reference point is is far more useful. Also, speeds are measured relative to lightspeed. Ships typically cruise at .05-.1 light. .1 light is attack speed. Ships move at .2 light if they need to really hump it, but attacking at .2 light is rarely done since relativistic distortion makes getting a firing solution very difficult. The other problem with moving faster than .2 light is that time begins to distort. As such, ships rarely move faster than .2 light.
The fact that light has to travel is also taken into account. If a ship is 30 light minutes away, then all the information you have about that ship is 30 minutes old. You have to get real close (a few light seconds) before you can accurately target a ship. Redshift and blueshift are taken into account and let you know how fast/which direction a ship is moving, i.e. if two ships are moving away from each other, each ship sees the other one tinted red. Fleet commanders use a holographic display to see what they call the "visibility sphere." When a ship jumps into a system, the light reflected off the ship moves outward in a sphere, and until that sphere hits other ships and planets in the system, they don't know the new ships are there.
Basically, a commanders most potent weapon isn't his actual weapons - it's the intelligent use of the physics of light that wins battles.
One thing that I've been curious about is how that would apply to a weapon that travels at light speed, such a laser or a particle weapon. The four weapons that ships use in The Lost Fleet are missiles, mass drivers (both for ship-to-ship combat and, more commonly, planetary bombardment), null-fields (which break down the atomic bonds of the target and turns them into a sort of particle fog) and hell-lances. As far as I can tell, hell-lances are either particle beams or liquid lasers. (
High
Energy
Liquid
Laser? I dunno, they never say if it's a laser or something else). Given that the lance is moving at light speed (a particle beam moves at light speed, right?), the target ship couldn't possibly see the weapon until the exact moment it hit the ships shields/armor, right? Would a ship have any way to detect an incoming laser/particle beam? If a ship could, it could theoretically use point-to-point particle weapons (a defense grid) to disrupt incoming beams or pulses... but only if the ship could see the incoming beam, which I don't think is possible.
Is there anything else I'm missing about a theoretical laser/particle beam weapon?
Sorry about the huge post. I've been pondering these things for a while.
There's actually more (ship roles, marine ranks) but these two are the most pressing.