Older gaming experts might remeber this genoius game called “Ports of Call”. Ports of Call is a trading simulation developed in 1987 originally made by Aegis Interactive Software. In the beginning you buy a ship, which you will need to transport goods and gain money. With the earned money you can buy better ships and the whole game adds up more and more.
Here are a few more details from the author:
Ports of Call DS is now in beta testing and most of the bugs are ironed out. I still have a very irritating bug to hammer out. This one causes your ship to crash in a harbor when a few very special conditions are met. I am now able to reproduce the bug and thats 90% of solving it.