If you change your mind and decide to stay close to port, you could have a really nice day on a walking tour within Valpo. I can recommend that you contact the folks at The Yellow House B&B www.theyellowhouse.cl to set this up. An Australian proprieter who really couldn't be nicer, and his Chilean wife run this cozy b&b. A local Valpo resident will be your guide and he does a great job explaining the city and giving you some back stories. If you don't speak Spanish, his English is excellent.