What a disappointing experience. This company seems to have sold way more Groupons that it can reasonably handle. Unfortunately, I went on my harbor cruise (well half of it), on a full priced ticket.
First, our boat was 20 minutes late arriving, ostensibly due to "traffic on the harbor." The first officer who was narrating the tour, wasn't bad, but the captain sailing the boat was incredibly rude to passengers.
The tour basically duplicates the routes that any public ferry will take to the island for a cheap price. Then it wends its way through the channel.
Here's the problem: They let you off at the grandstands so that you can explore the islands. Unfortunately, they are utterly unprepared for return traffic. We waited an hour and did not succeed on getting on either of the two boats that came for the return. There was no organization, and no way to wait in an orderly line. The boats were so full, we were forced to return via the public ferry. I never got the second half of my tour, hence the one star rating.