I just received some good information for anyone who is planning to take the Bacardi Rum tour. I asked him what it costs to take a cab rather than the ships intineary charges of $28 per person. This is what he wrote back.
There are no charges for the tour, it's definitely free. And your best bet, if you are at Pier 1, 4 or 6 is to walk to Pier 2 which is where the Cataņo ferry boat departs from, take the ferry across the harbor to the little town of Cataņo - I think it runs 50 cents per person. As you leave the ferry terminal in Cataņo you will see a bunch of vans - these are "publicos" and they carry people to and from Bacardi for a very reasonable fee. I'm not sure how much they charge, but ask and you'll probably get an honest answer. This is a real fun way to do it, and definitely the least expensive way.