When you have the ship hold ''A'' and press ''B'' 55x. A sliding puzzle will appear. Put the numbers in order and you win 100gp.
When you play the boat mini-game (hold A and press B 55 times on the boat to play) you will notice three seperate times on the top-right, going from lower to higher. These are times you can beat for a lot of extra cash. Here are the rewards:
If you complete the mini-game in under the time on the bottom, you get 2,000gp.
If you complete the mini-game in under the time in the middle, you get a 5,000gp.
If you complete the game in under the time on the top, you get a wopping 10,000gp!
If you don't beat any of those times, well, you get just 100g...
The following trick is an easy way a receive money and experience. As soon as you get the ship, go back to the first town and spend the night. Then, turn off the power, continue your game, go directly to your ship and go south. You will meet one to six Kyzuku. Go back to town, save, turn off the power, and repeat as many times as desired. Note: This does not work if you reset the NES, you must turn off the power.
Inside of the Ice cave (the one with the floater) is an Eye protecting a chest (with the floater in it). The Eye is worth 800 experience and dies in one or two hits.