How do I leave this Island?Edit
I'm sorry I can't let you leave this Island without lligith's permission.
He is probably at his inn, so you will find him there.
How do I use the raft?Edit
Just go down to the beach and step into the water and you will be able to travle the shallow waters.
You can't venture out on the deep sea with a simple raft, but I am sure you will be able to find a better ship in in west lockwoods.