I have used this service before and they do a great job. This is the same bus service that brings you to and from the ship(s). As you arrive to the location [from the ship] where they meet [across the street from McDonalds] they will sell you several packages including horseback riding, ATV tours but we have used them twice to go to La Bufadora.
My cruise company told us that if you don't use "their" service, you could be left if you are late and that is true. The first time I took at trip with Misioneros was on a holiday weekend but we were not aware. Traffic was horrible but we made it with plenty of time.
Our guide, Pricilla, and our driver were great. They introduced us to several restaurants at La Bufadora as well as some other vendors that they have vetted [and getting a commision, I'm sure]. read more