I played the third one a few years ago, but I wanted to replay it before the fourth, though I haven’t been able to get it.
Today, I uploaded the beginning of Black Flag and plan to post one or two each week.
I hope you enjoy it, and if you have any suggestions for improvement, I'd really appreciate it.
I'd suggest you to explore the islands and do the side activities like fighting a shark maybe? You'll get the best out of the game if you explore the side activities.