Lest any get the wrong idea, the Sea Cabin is about 8 x 8 (that's feet, not meters), with an equaly small head, say 3 x 2 attached. All of the plumbings, electrical, and ventilation protrudes from the walls and is not buttoned up.
As was pointed out above, the Captian is responsible for all actions of his ship, awake or asleep. So, such sleep as is possible is mere steps from the Bridge, where junior officers are taught the nuances of watchstanding and ship's navigation.
The in-port cabin might be as luxurious 10 or 12 by 12 or 14 feet, with a proper washroom attached. The mechanical s are behind panels for a neater look, too. There's a "day cabin" on some ships, where the CO has a desk, perhaps even a couch.
For ships designated/designed/meant for flagship duty, there will be a replica of the Captain's quarters. These are the Flag Sea Vabin, and the Flag In-port cabin. Flagships will have a couple of staterooms for the Flag staff officers. In the days of old, battleships even had a separate Flag Wardroom. There was a Flag Bridge, too--no helm or engine order telegraph, but repeaters for all pertinent navigation and sensors.
I'm pretty sure the Tico's only have the two cabins for the CO. You fight the ship from CIC; but you navigate from the bridge. At least with surface combatants. CO spends a lot more time worrying about running over a lost cargo container than in CIC.
The persons who ought to have a cabin by CIC are Ops and Gunno--they live in CIC.