Wearing the suit of Navy Blue, I have served on a couple of her Majesty’s war canoes, and there are “Port” holes on the Starboard side too. They are thick glass , very tough, and on thre inside, they ate fitted with a steel shutter called a deadlight which blocks any light that would give the ship away during hours of darkness, and provides a modicum of watertight integrity. Because we were serving in the Persian Gulf, we were allowed to open them at night to let a little cooling air in as every thing was so *?$%& hot. The second time we went up there, the ship was air conditioned, which was wonderful, so if you want your model to look auyhentic, you can fit thr outer part of the scuttles (portholes)but not glass that a viewer could see through, and a further authentic touch, model men flaked out in the shade of anything and everything on the weather decks
i.e those decks exposed to the outside air and flying fish.