“ I guess I could teach you how to swim...but...
Oh, no more bananas. I'm kind of tired of them...
But I'm really thirsty. Do you have anything to drink?
Give Charles some Banana Juice to quench his thirst.
Talk to him by stepping on the bridge and then take the banana's to the miner who is standing outside Village of Civilization and give him the Miner's Hat from the previous event to make him go inside. Head after him and go to the Clock Tower. Talk to the miner inside and he'll turn the bananas into Banana Juice.
Go back to Charles and give him the Banana Juice to clear the event.