Here is a breakdown of the game idea:

I am interested in building a game of maritime trade in the period of the last century between ports in countries:
Start with a small ship and a small amount of money to buy, transport and sell goods such as: wheat, fruit, liquor, water, and the like. Depending on the prices of the goods advertised in the ports in the different countries in order to maximize the profit from their sale.
You can also transport goods, other people's luggage from port to port for a freight charge only.
When a suitable naval crew has to be purchased for the operation and protection of the ship against pirates and if you encounter and overpower the pirate ship, you can take all the booty of the ship.
When you accumulate enough money, you can buy more advanced and modern ships, for transport in larger quantities and I have more protection against pirates.
Must be in the game: map of the ports in the world, weather forecast and storms at sea, sailingdays between each port and port.