I don't have this game anymore because I traded it for Harvest Moon. Here is the cheat I used to win the fishing competition. If you don't have a fishing rod, Tortimer will give you one on the day of the competition. Once you've got it go time travelling to August and go down to the beach. Wait until you see a fish with a fin sticking out of the water. This will either be a Shark or a Ocean Sunfish . Either one will do. Then go back to Fishing Comp. day and give the fish to Tortimer. If you can't be bothered waithing, time-travel to the next day and, Tada! You've won!