Absolutely. Are you going to try to get a phone number or EMail address for the tour guide?
I also posted, on cruise addicts, and received no responses (although one person did post and say that we would probably have no trouble filling a van after we boarded the ship). However, I am the one who would be out the balance if we don't, and I am concerned because Puerto Montt is our first port, after only one day on the ship, and I'm not convinced we would be able to fill a van, or even come close, in that time frame.
So, certainly, check it out, and Sheila and I will be game. We are NOT bus tour type people, and welcome any alternatives.