The ship is part of a larger world with a complex backstory that I have been building for several years. This is the flagship of the Royal Fleet.

As I said before, this ship is part of a rather large world I've been building for 5 years already. 
As for the interior of the ship, as well as in general, I am still relatively uncreative, so that much looks very similar. I therefore ask for general suggestions.
First pictures of starboard and port in long shot:

As you can see, it is a three-master. I'm not happy with the size of the masts, to resemble original ships they would have to be bigger, but then they would possibly cover the building in the background (not yet finished).
Fortified with 9 cannons (The Great King, whose personal flagship it is, has a monopoly on gunpowder production, so 9 cannons is a massive firepower in this world), the ship is equipped with about 130 beds. From gunners to sea soldiers to sailors, everyone has their area. 

This is the upper deck with the rudder, a compass but otherwise still very plain.



From the main deck you come to the officers area, there are some higher officers a place to sleep, also there is the officers mess and the captains cabin. Also here I am happy about suggestions.
A staircase leads down to the map room:

Now I show exemplarily some pictures, to follow the exact construction of the ship would be very time-consuming:



Crew quarters

Sea soldier quarters with armoury

"Wallgang" around the soldiers' quarters. This deck is just above the waterline, from here archers fight approaching ships from cover with incendiary arrows.

Now follow the mess hall, butcher shop, drinking water supplies and hold (a small part of it anyway

Here now the upper gun deck with the three bow guns:

This is the lower gun deck. On the second picture a loading hatch leads down to the magazine

The lower gun deck is partly under the open sky, here the top view:

That's it so far, if still certain images are desired, I deliver them with pleasure. Otherwise, I ask for ideas, how I can make the interior of the ship more detailed and especially more vivid. 
Also, I hope you like my ship, and if you do, I'm sure it won't be the last one I upload here.