Unfortunately, there are a few issues I can see if you want it to be realistic. First off, medieval Galleys tended to have a curved shaped on the deck. Not to an extreme, but a bit more noticeable than what you have here. Second, while you got the lateen sail focus right, the bows of galleys looked totally different from the age of sail ships. Their forecastles were more like covered or raised platforms under which the cannons would be mounted and from the tops of which marines would board enemy ships once engaged up close.Further, cannons on galleys were generally mounted centerline only-- peeking out of the forecastle area. Cannons that were mounted on the sides were generally smaller swiveling guns. Here for example is a galley used by the Knights Hospitaller in the 16th century around the Lepanto times. This is more what galleys looked like in general.Now, all of that said, I don't know much about the enormous Venetian Galleasses and they could have been rather different, however they probably had a similar design.All of that aside though, this is still a very nice piece about a part o history that is not often talked about in modern day media. I love seeing it portrayed and the fact that you evento make it accurate is more than can be said for a lot of people that try to draw Medieval settings.