I have friends that visit me in San Pedro when they stop off on the cruise ship but they fly out of Municipal. The problem is, when they are unloading people off the ship, the people who have scheduled tours get first priority which means you might not get off the ship until 9-9:30 and would miss the boat. Even when my friends fly in, it only gives them a few hours on the island before they have to get back.
IF they offer a trip to Hol Chan/San Pedro right from the ship, I would tell them to sign up for it.