In that game, I got ships earning around 160,000$ a trip. Granted, they did not make many trips in a year, but as soon as I get a steady flow of ships coming from the rig to the dock, then the cash can't stop coming in!
The best part is not the ships. It is when I build an airport or a train station to get all the goods from the Oil Refinery...
Then the cash really flows in!
Edit: here is a screenshot of later in the game since I continued playing and are now 20 years later than the first screenshot. I wish to take your attention on the cash the boat at the dock just sent in my bank account... And I hope you get the point.
