The “skill” of using a snorkel is a nuisance as during the diving it keeps getting in the way. I don’t believe there is a difference really in removing the the system in the water and putting it back on. It’s 2 straps just like a BCD. The skill of swimming from about 20 ft to 50 ft, back to 20 ft, and back to 60 ft was not kind on my ears. It was a skill just to show that your buoyancy remains stable. You have to fill the tank with water for 2 full fills, approx 2 1/2 mins, and basically swim upwards for x amount of time to show how much weight is in the tank after adding all the water and how to keep from sinking. Also the opposite without any water in the tank so you have to kick to stay under. I guess what made it the most annoying was that I wasn’t prepared to do all of this. We didn’t feel like we had the chance to explore the system. I think you could do the skills on your first dive and “enjoy” the second dive. Our first dive was only 32 minutes I believe and still had about 50% air left. Second dive was similar. Just my thoughts. I think it all started when we showed up at 830 and they said we would do some classroom, one dive, take a lunch break, do another dive, do some more classroom, then finish up about 4pm. Didn’t really know what to expect but it definitely wasn’t that. Maybe I was just grumpy that day but that’s how I felt. It didn’t help that our instructor seemed annoyed anytime we asked a question to clarify a question or procedure. Then it became annoying to us when he didn’t seem to understand how we couldn’t understand what he was saying. Maybe a slight language barrier? I don’t know but he didn’t seem like he was having a good time.