Here's a pic outlining the crew structure of a typical cruise ship (I'm sure somebody can find and post something similar for a large warship):
I looked, the only things I found were WW2-era and a proposal for some new structure that hasn't been implemented.
https://www.ibiblio.org/hyperwar/USN/ref/Seamanship/img/Seamanship-7-2.jpg is the WW2-era chart for destroyer-sized ships.
I imagine the Navy doesn't make its current org charts public knoledge, but in the context of Traveller ships, High Guard actually gives a rough outline and I read between the lines a bit.
My cut on High Guard's Org structure:
Command department gives a number of Officers and Enlisted - listed as the commanding officer, an executive officer, a computer officer, two navigation officers, a medical officer, and a communications officer, plus support ratings. I assume the Enlisted are Bridge watchstanders who actually mash the buttons as instructed by the Officer in charge at the moment. I lump the Navigation department in with this group, since two Navigators are part of the minimum crew. No nav enlisted unlike RL because Traveller navigation is very simplified and streamlined, there's no mass of charts to organize or positions to plot continuously - these are all done by computer in Traveller, it seems.
Flight Department is obviously composed of pilots and maintainers of subordinate craft.
Engineering Derpartment is comprised of people who work on M-Drive, J-Drive, and the Power Plant. I divide the Eng Department up based on the tonnage of each section. Petty Officers are work center supervisors and Officers are Division Officers. Large ships with lots of Officers and Petty Officers get broken up into Auxiliary department, who work on life support, and other related things like structural repair groups.
Service is 3/1000 tons, or 2/1000 tons if you're going to dragoon Marines into the untrained jobs. I lean into a more tranied and professional force, so I go with 3/1000 regardless of my marine complement, then I don't have to worry if I've embarked too few marines. Service is an overarching division, comprising traditional Supply roles like food service and ship's store and barber shops, and actual support groups like (non-Engine Room) equipment repair, Sensor and Computer repair, and Comms operation and repair. It's one of the more numerous groups on the ship and this is why - all the roles it needs to fill. This is why I'm fine with the full 3/1000 figure. POs and Officers map pretty well to Work Center Supervisors and Division Officers, with the exception that the Computer Officer and Communications Officer from the Command group honcho those subgroups under Service. Extra officers get mapped into galley, so I have separate officers for crew galley and the Wardroom, and the two Parts Supply departments, one for regular consummables like food and one for repair parts that are needed at any given time.
Medical is a tiny division, but it is what it is. Presumably led by the Medical Officer required by the Command section.
Gunnery Department is pretty cut and dried, you need 1 gunner per turret, 2 gunners per bay, 4 gunners per screen. The Petty Officer and Officer requirements are generally Division Officers under the primary Gunnery Officer Department Head, and the 'Petty Officers' are generally the work center supervisors underneath each division.
Marines are apparently supposed to be organized per book 4, but I've never dug the details out of that book, and looking at it, it's pretty vague anyhow (A squad will consist of two
or three fire teams, a platoon consists of up to three squads
or two sections), so I just ballpark a figure of 25-person squad plus 5 high grade NCOs, and a platoon officer (~1Lt) plus 2 subordinate officers (~2Lt). That gives me a Platoon of 33 people, which fits neatly in a Pinnace, and gives a bit of resilience if the platoon commander is taken out. Book 4 can generate platoons from 24-48 people, so 33 is close enough to the middle. 32 is one of the choices Book 4 offers, so I think I am OK.