The actual sea itself, I mean. With so much trading going on, I would imagine there were a lot of ships going around at any given time; How many other ships would you normally have in sight on a voyage? Would it be significantly quieter at night? And would there be more merchant and cargo vessels, or armed escorts?

As a side question, are there any good documentaries or books on the trade in that period?

I ask partly because in the game Europa Universalis IV, the sea is absolutely packed most of the time, with multiple fleets in almost every seazone, and Im not sure I can trust the specific accuracy of a game where Ming can field less than 60 thousand men...