"It's so easy to assume you know how to snorkel. People grab some equipment from Walmart and hit the ocean (usually for a $300 expedition). But this class really provides the foundation- how to choose equipment for example. We learned that even though our equipment came from professional dive stores, my husband ended up with a scuba mask and not snorkel mask (And yes there is a difference). Even though we have been snorkeling all over the planet (from Hawaii to Fiji, to the Caribbean, we still learned new and important information. I would highly recommend this course to anyone before going out on an expensive snorkeling tour. You will get so much more from your tour."