Hell yes! I grew up with that (In the UK), it was one of the first books I read (And series I watched) in the 80's/90's... introducing my daughter now to them.
12 Trials is still something I quote to my wife at times... "You are a wild boar, a wild boar" :D
The Russian ports on the Black Sea are so absurd that if you encountered a setup like that in a video game you'd just quit because it's unrealistic.
Scenario:
Game: Ok, you've got a port that's open year round with access to both the Atlantic and Indian Oceans.
Player: Yay, I set sail for the Atlantic.
Game: You set sail, making good time across the Black sea. To continue to the Atlantic, you first have to pass through the Bosporous, a narrow channel that goes right through the biggest city of Turkey. You need to make it worth their while.
Player: This is bullshit. Ok, I bribe Turkey, now am I in the Atlantic?
Game: You've made it past Turkey. Are you at peace with Greece?
Player: Yes... why?
Game: Congratulations, you are able to pass the Agean sea. You have now made it to the Mediterranean sea.
Player: Wait, I wanted to go to the Atlantic.
Game: To go to the Atlantic, proceed to the Strait of Gibraltar. Are you at peace with England?
Player: What? Wait, this is bullshit. Another strait? And isn't England up in the northern Atlantic? I'm at peace with Spain, France, Italy... what does England have to do with it?
Game: England controls the Strait of Gibraltar.
Player: This is bullshit, ok, I go to the Indian ocean instead.
Game: Are you on good terms with Egypt, Yemen, Eritrea and Djibouti?