You do need to learn how to use a DS, you can either bust right through it and take the class, or find an experienced buddy and invest a couple easy dives, personally, I went to DUI Demo Days twice a year or two ago, did 4 dives in a suit with DS instructors in the water and about a month ago I did my longest cave dive yet in a somewhat poorly fitting DS (with completely different equipment from my Demo Days!), so it can be done.