The best way to build up money in the whole game is trading. After you get started you should sell then buy then sell then buy. The key is to get a good bookkeeper, you can find 3 good ones in these places usually. Antoine Fitch- London, Jacob Walwiek- Bordeux, Benito- Alexandria. You must always buy the lowest possible and sell the highest that you can. The routes are: Hamburg to Copenhagen (buy dye and glassware), Istanbul to Athens (buy carpet and art), then there is Cairo to Mecca (the specials of both).
Better ships
You can find better ships to fight with in Sakai and Nagasaki. The easiest way to get there as soon as possible is to trade carpets and arts until you have around 10,000 gold pieces. Then, buy glass beads in Venice and sell them at the port of Madeira. The beads will cost 2 or 3 gold and can be sold them for about 50 gold. In Madeira, buy sugar for 12 gold and sell it at the port of Santa Cruz (1 day of sailing south of Madeira). Buy flax from Santa Cruz and sell it in Amsterdam. From there you can buy glass beads and repeat the process. Do this until you get to 20 gold ingots. Then get some balm in Barcelona and cruise to the far east with a small ship (preferably with rows like a LaReale) with high velocity (such as a Caravella Redonda). First, stop in Nagasaki and invest 50,000 gold at the shipyard. You should do this when you reach the end of a month, as it is faster that way. When the month changes, you should find an Atakkabunde (cheap and efficient). Buy it and remodel it to only support 30 crew members and no cannons. If you have mates that can pilot ships, then buy a couple to speed up things. In Nagasaki, buy silver and sell it in Changan, Zeiton and Sakai. These ports have silk items; buy some to sell in Nagasaki. If there is no silver, buy porcelain. You will get fair price for porcelain in India -- the clove and pepper are cheap in India and sell for ten times higher in the Far East. Five months in a row, invest 50,000 in Sakai or Nagasaki. When they reach 1000 points in the shipyard, you will find a new boat: Tekousen. This is the ultimate battle ship. It is row powered, which is good when the wind dies, and can reach up to 20 knots in speed. Remodelling the Tekousen only permits you to hold 300 crewmen and up to 100 cannons. Another trick: buy a used Tekousen. It will hold 360 crewmen and 80 cannons. It is easier to maneuver in battle, and it has more speed than a Venitian Galeas. It also has as much cargo capacity as a full-rigged ship or even a barge.
Black market
Wait until 2:00 a.m. and go to the item shops at the ports. The Crusader Sword may be found at the shop at Timbuktu.
Building the "Barge"
Go to Bristol and invest $50,000 in the shipyard every month for 3 to 5 months. When this is done, ask the shipyard worker for a new ship. He will show you several new ships including frigates and Barges.
Building the "Full-Rig" Ship
In Hamburg and Antwerp you can purchase the best battle ship in the game, when arranged correctly it can travel the most days at sea also. Invest 50,000 gold into the shipyards at Antwerp and Hamburg from 3-5 months. After 3-5 months then go to the shipyard and go to buy new ship, on the second page of ships you will find the Frigate and the Full-rig ship. If you invest in both at one time then you can build two at a time. They are better than the Barge in battle and at sea. But the best trade ship is the Tekkhouson, after investing the same amount the same amount of times in Sakia then you can purchase a Tekkhouson. It is the best trade ship. Arrange it at first then sail back to Europe. It is the quickest ship and it can hold the second or third most cargo in the whole game.
Carronades
Head towards Bristol and invest in both Shipyards and Trade Market. Keep them both invested with the same amount of money, $50,000. After you have gotten the Barge ship, invest once more in the Shipyard and Trade Market. Return next month and remodel your ship's guns. The message "Your in luck, we have a new specialty today" or something similar should appear. If this does not happen, leave the Shipyard menu and keep returning to remodel guns. The new gun is Carronades. Its attack power is as strong as a Cannon, and its range is as far as a Culverin. This is the most powerful guns in the game.
Crusader's Armor
Go to Naples at 2:00 a.m. and purchase the Crusaders Armor. It is also star class armor, but it is a lot better then the Errol's Plate, which is cheaper.
Easy Battle Experience
Go to Tunis and pick out a week pirate to prey upon, then when he comes out bombard him and challenge him to a duel. Make sure you are well equipped with a B or better sword and armor, when in the duel have him at your mercy by keeping at a 50 plus or minus ten life points but don't kill him. Use weak one level attacks until he can survive a blow.
Keep that up for 10 attacks and the duel will end. Then challenge him again and again until you have your desired level. note this works best if you have a Barge ship and have sunk all other ships around so you can duel away.
Easy Money
Deposit money into a Marco polo bank at the end of a month then stay in the lodge until the month is over. Then return to the bank and you will receive 3% more than you deposited. Try this every month for easy cash. The more you have, the more you get.
Errol's Plate armor
Go to the Black Market in Copenhagen to get Errol's Plate. That is the star class armor, which is even better the Pull Mail Armor.
Faster Battles
Hold Y on the battle field when it's not your turn for a super fast battle.
Merchant discounts
The Merchant will always discount the price of his goods at the rate of 75.0% of the full price. For example: If you were buying Porcelain for 108, do not pay more than 81. You will be able to get this discount even if you do not have a good bookkeeper. The key to getting this discount is to make sure the port is allied with your country (and also not a neutral port). You do not have to have a Tax-Free Permit, but it will reduce your price even more. Also, if you have a bookkeeper, they will do all the work for you. This is a rather short list of the bookkeepers: Esteban Ortega, Jacob Walweik, Antoine Fitch, Benito Gomez, and Tristan Seillo.
Reduce Attacks
This code is simple. Enter your name as "Black Beard" and you almost never get attacked. Also, some of the ships will actually just give up when you attack them!
Stat Boost
Upon starting the game, refuse the stats about 75 times and suddenly you’ll see the stats greatly increased. Patience!